I am wondering if certain food became more popular in China after or during the Cultural Revolution or if certain recipes or culinary traditions actually ceased to exist or became more rare.
Due to heavy food rationing (partially caused by the catastrophic failure of the earlier Great Leap Forward) cuisine during the Cultural Revolution was very simplified. People made do with what was at hand...they might go fishing, they might grow some vegetables for themselves, if they were in the country they might try hunting and gathering local plants. It was basically survivalist cuisine.
How does that translate to modern cuisine? There are some restaurants in China that replicate the type of food and cooking styles that would've been needed during the Cultural Revolution - cooking with little to no oil, for instance, or using ingredients found nearby (like wild grass).
These restaurants are interesting in the sense they're not representing a desire to go back to those days, but rather to allow people to remember and reflect on what happened. So part of their appeal is historical and part of it represents a sort of nostalgia for those who lived during that period.
Untidy sources as I'm on my phone:
There was a spate of anti-intellectualism during the Cultural Revolution which struck out against and repressed all forms of expression and extravagance. This affected everything from martial arts, to authorship, to cooking.
From 1966 to 1976, Mao Zedong promulgated and enforced a strict policy of rationing and austerity. Food was scarce and millions were driven from the cities into the country where cuisine was rarer still. Every aspect of your life was subject to governmental influence or control, from your movement, occupation, expression, and even thoughts (a sort of mass brainwashing was key).
In communist propaganda, the countryside was put forth as idyllic, filled with nature's bounty... but in reality, it was merely a move to lower population density and the ability to collect into dissatisfied resistance. A bunch of urbanites thrust into the country to starve and die.
This, of course, affected cuisine. Generally, cooking was simple, local, and peasant food. Similar to the development of British cuisine during the Blitz and rationing.
NPR Resources:
Chow Under Mao: Surviving China's Cultural Revolution On Local Food