The short answer is yes, but of course it's much more complicated than that (it always is!). I can speak a bit to the music of Central Asia under Soviet rule, which can illustrate some key points very nicely. Hopefully others will be able to answer for other areas and musics.

One thing to always remember about "folk music" is that it's largely a narrative. Popular music is, well, popular music. It's the music that a lot of people play and sing and listen to, and can change considerably. If after a while people stop listening, it's no longer popular, and can fade out of the general consciousness.

Folk music is different mostly because we tell ourselves it is. It's often music that was or still is popular, but it's also music that we have deemed has some kind of essential cultural value. For example, the instrumental dance music of Ireland was once what you'd hear being played on a fiddle or concertina at a house party there. To some extent it still is (you've just got to go to the right parties!), but it has taken on the added symbolism of something essentially "Irish." It is promoted as a part of a broader "Irish" identity, and even though playing it is a minority interest inside Ireland, it has a highly significant role in both internal and external concepts of "Irishness."

I use Irish music as an example because it's much more familiar to most Western audiences than most of the music of Central Asia. But the same processes are at play there, and most certainly were during the Soviet era. If you go to Krgyzstan, for example, you'll learn that the komuz, a three-stringed lute-like instrument, is regarded as a national symbol. The same is true of the dombra, a similar two-stringed instrument, in neighboring Kazakhstan. These and other instruments have similar narratives around them, including an ancient origin, a longstanding tie to the inherent culture of their homeland, and a long line of masters and well-respected players/composers. Curiously for instruments that developed among diverse and rural cultures that didn't always have access to centralized instrument makers, music schools, etc., they also often have standardized forms, standardized playing styles, standardized scales (often quite similar to Western scales!), and standardized repertoires. And while national borders are just lines drawn through areas with highly fluid and changing boundaries between peoples and cultures, many of these musical instruments seem to follow these national boundaries fairly closely. This is where we start getting into Soviet influence on the development of folk music in Central Asia!

I want to be clear when I say "narratives" or "what we tell ourselves" that these aren't made up in the way you might think. No one was going around and inventing instruments no one had ever seen before and pretending that they were somehow ancient. Instead, what happened was a distillation of various highly varied cultural traditions into more standardized forms, which were then promoted as the true folk music of a particular people. This was done for a number of reasons, including to foster social/cultural cohesion and to put greater focus on the goal of "uplifting the common man."

To say that the USSR had a complicated relationship with the many, many ethnicities and cultures that it contained is an understatement. Broadly speaking, the promotion of folk music that we're talking about in Central Asia starts in the 1930s under Stalin, part of larger reforms throughout the country. The basic premise was to steer folk music in a direct that was "national in form and socialist in content." Folk music was seen as important to the identity of the common man, but also in need of the same kind of "modernization" as other aspects of "peasant" life. As Western music in general and Western classical music in particular was the prestige music, this meant shifting many of the concepts of traditional folk music to better match the values of Western classical music. Folk "orchestras" and ensembles were created using instruments that in many cases would normally have been played solo or in small, specific groupings. To facilitate these, as well as playing alongside Western instruments, the folk instruments themselves were standardized and redesigned to fit the Western 12-tone scale and concert pitch. These ensembles featured prominently in media, and performed both at home and around the USSR, promoting their country's music.

The reform of folk music happened alongside a general promotion of classical music into areas around the USSR. Opera houses, ballet theatres, and concert halls were built and musicians recruited for their ensembles. Local composers were encouraged to blend folk music in with their classical compositions, either for standard orchestras or for blended ones using both folk and standard Western instruments. By doing so, they were both taking local ownership of Western classical music and "lifting up" that peasant-derived folk music into something more generally seen by Soviet higher-ups as "Art."

This had some very clear and drastic implications. For one, the cultural center of folk music shifted into urban areas. These were the places that had the music schools, the concert halls, the recording/broadcast studios, etc. It also radically changed the concepts of professionalization and pedagogy in traditional music. Before, master musicians would have traveled for work, usually in rural areas, and students would have followed suit, becoming an apprentice to a master for a time before becoming independent working musicians on their own. Now, instruction happened at music school, and your best bet for a job was in a government-sponsored ensemble.

It also had effects on the ways in which we see instruments. The komuz and dombra are two iterations of an instrument type that is  widespread throughout Eurasia. The Mongolian topshur, the Tuvan Doshpuluur, the Persian tanbur, the Ukranian dobza, and tons of other instruments are all ultimately related. Given the massive distances involved and the highly variable nature of folk music, it's easy to see how these different iterations developed. Yet they are all very distinct and very specifically tied to a particular ethnic group. This isn't historically the case; why would an instrument in Almaty be more similar to one in Nur-Sultan (over 1,000km away) than one in Bishkek (less than 250km)? The answer is that the national boundary, a political one with political implications in the USSR, is very important!

The instruments themselves changed, both in terms of the scales they played, the standardization of their form, and their purpose. Rather than being played in intimate settings, they needed to have a more robust tone suitable for larger halls and playing with ensembles, while also being able to blend well with others. They also often subtly moved towards western counterparts. For example, in Kazakh music bowed instruments like the kyl-kobyz became a bit more like a violin, frets were added to the dombra like a guitar, etc. In some cases Soviet instrument makers actually went to "help" local instrument makers "refine" their own ethnic instruments!

The instrument could now also be used as a sort of stand-in for a people in cultural presentations. In fact, one presentation that has remained popular is a sort of "battle" format, where two masters are sat side-by-side on a stage to highlight both the similarities and differences in their respective national musics. It's again a way of asserting national identity while also recognizing a sot of shared heritage, important for feelings of social cohesion.

Finally, it had effects on the way the music itself was viewed. It now occupied a place of official prestige similar to Western classical music, and was a worthy endeavor for people of all social backgrounds and classes. The Western academic approach to the music, placing it in conservatories and institutions of higher learning, brings the music into what Westerners would see as an "intellectual" realm. This continues to this day, and folk music is in many ways much more an endeavor of the educated middle class now than it was before.

Why would the Soviets do this? Because folk music can be a massively powerful symbolic tool. Promoting folk music in a centralized, standardized way gives everyone in a region a shared, collective identity, one that just so happened to be tied up in the Soviet system and its political ideals. And it's worth noting that not every ethnicity/nation got this promotion of folk music, nor did it happen equally throughout the country's history! One notable omission in much of this is any music of a religious nature, although this was not as much of a consideration in mostly-Muslim Central Asia as it was elsewhere.

Sources:

Atai, Farhad. "Soviet Cultural Legacy in Tajikistan." Iranian Studies 45, no. 1 (2012): 81-95. Accessed April 24, 2021. http://www.jstor.org/stable/41445198.

During, Jean. "Power, Authority and Music in the Cultures of Inner Asia." Ethnomusicology Forum 14, no. 2 (2005): 143-64. Accessed April 24, 2021. http://www.jstor.org/stable/20184516.

GOLDMAN, LEAH. "Nationally Informed: The Politics of National Minority Music during Late Stalinism." Jahrbücher Für Geschichte Osteuropas 67, no. 3 (2019): 372-400. Accessed April 24, 2021. https://www.jstor.org/stable/26903864.

Muhambetova, Asiya Ibadullaevna. "The Traditional Musical Culture of Kazakhs in the Social Context of the 20th Century." The World of Music 37, no. 3 (1995): 66-83. Accessed April 24, 2021. http://www.jstor.org/stable/41699054.