If nothing else, Bluesky will serve as a quality filter for the fediverse in the same way Truth Social has.
Celebrities are largely dumb and need a platform that holds their hand, and they found fedi too confusing.
Since Bluesky aims to be a Twitter clone where the federation is a technical thing in the background rather than something they're forced to understand, they find it easier and will migrate there, leaving fedi's culture to continue as it has been