This is more a lemmy thing. Tankie is an older word but like you dont usually run into stalinists in the wild too much. The Lemmy creators and one of the biggest instances when the site was still small was a communist one promoting not just like the ideal of communism but legit stalinism.

As a result there was a lot of weird very pro russia pro china pushback and whataboutisms on the platform in the early days before the number of non stalinist users drowned them out