It feels like .world is going to defederate soon, which will likely result in a multipolar Lemmy. Leftists and Leftist-aligned communities, and Liberals and Liberal-aligned communities, with hands-off communities like Lemm.ee being visible on either.
At this point, without any active Marxist communities, and defederating from almost all overtly Marxist instances, it is pretty obvious .world is anti-Marxist, so I doubt Marxists will stay with .world accounts.
Considering .world has a far less leniant defed policy it might just collapse on itself and the user base go back to Reddit, but that won't be a rapid process.