No, I'm not even interested in the surveillance here (though it is also a good comparison). Full disclosure, I'm very pessimistic on what current LLM models are capable of, and even more pessimistic on the impact of social networks.
I'm referring to the control of interactions and information. Take a look at the character interactions on the novel.
People socialized as they could, but interactions were not only heavily monitored (to your point), but altered as well. Winston struggles to behave correctly in public knowing that one small misstep could result in him being arrested by The Party. He revels in the chance to rebel against it, only to find that the opportunity to do so was in fact a trap. Even the allowed language was neutered as much as possible to prevent communication. All of these virtual 'friends' will likely politely comment and correct your posts as they see fit.
As for information, "we have always been at war with Eastasia". People in 1984 were clearly being fed false information as part of control. History was altered, facts were changed, it was pretty heavy handed. But imagine what this personal echo chamber could do with a new concept or idea (that virtually all parties you interact with corroborate, along with LLM generated 'news' posts and generated pics that support it), how many people will verify? Just think of how many folks you've seen have been misled by a single well-done "fake news" post; now, imagine that the network itself is confirming it at every turn (note Meta owns multiple networks).
Oh, and as a bonus, these virtual friends are really enjoying Brand Product. Have you tried it yet? Folks keep posting pictures of themselves with Brand Product, and they look pretty happy!