I'm asking because I was reading a book about Siberian folk religion written by a Hungarian academic in the 1950s and it lays on the ideology pretty thick, talking approvingly about the "need" for Soviet authorities to proactively crush said folk religions rather than merely letting them "die out", which is somewhat at odds with trends in Western academia supporting the rights of first nations. I wondered if the inclusion of this kind of orthodox communist ideology was a prerequisite for getting your work published in communist countries before 1989.
I was also interested in subtler manifestations of this phenomenon, hoping that someone might comment with a rough guide to interpreting the writings of communist academics.
You are right to question his frame of mind. You haven't mentioned a title or author, but the timeframe and location does coincide with what would be characterised as Soviet Historiography. There are very few works within this type of historiography that are considered relevant in present day academics, at least as historiographical works.
That is not to say that these works aren't useful for a student of history today, you simply can't take them at face value. Some will be more academically sound than others, often depending on the subjec. Mostly though, the historiographical works written during this period under Soviet rule are so heavily influenced by different ideological narratives that it's difficult to consider them credible.
Naturally, this is true for most dated works. You need to be mindful of their context. What was the frame of mind of the author? During which time and historiographical phase was this work written? What were his intentions or potential biases. These are questions you should always be asking yourself. They simply become a lot more pressing for dated works.
However, I think that it's fair to say that a lot of works stemming from this period are so warped that they are mostly just considered to be a primary or secondary source - depending on the subject - and not actual academic literature. Keep in mind that there isn't some general rule to judge all historiographical works, so you'll have to share the title with someone who studied historiography in Soviet Russia extensively in order to get a proper answer.
I'm not sure if there is someone with that expertise on here, even if you were to share the title.