Anticommunist in that its orbiting around the hivemind genre of anticommunism which goes back to the red scare with films like "invasion of the body snatchers" (1956)

Invasion of the body snatchers had no references to communism or the Cold war, but the subject matter of the film, of conformity vs. Individuality, of being taken over by a unknown force, was fully in line with the themes of the red scare.

Pluribus is anticommunist specifically in that it creates a space where the "individualists" are all bourgeois who live in capitalist, neoliberal countries while the hivemind presents a fatally flawed "collectivity" that the individualists have a moral imperative to fix.

The Stalin line does count. Why choose Stalin and not Hitler? Even when the character of Carol delivers that line, there is no pushback to it. How sure are we that this is simply carols flawed hyperbole from her upbringing in-text or actually just a flourish for the writers on carols "character moment" at the end of the second episode.

Also associating Stalin with mass death has been the top priority for anticommunists since his death. It acts to delegitimize him and his contributions and to prevent people from reading his work itself and not second hand sources criticizing him (because who wants to read the writing of a mass murderer).

The line wasn't for nerdy commies, it was a dramatic remark to reinforce that communism will not be discussed in any way. Bravo Vince is also a liberal and liberals emit anticommunist brainworms.