Reading the tea-leaves, here's where we are in terms of US Fediverse migrations:
#redditMigration Chapter 1 (of X)
#TwitterMigration Chapter 3 (of X)
#MetaMigration (Facebook and Instagram): Avoided due to launch of #Threads
#SnapChatMigration Not started yet
#TikTokMigration Not started yet
#PinterestMigration Not started yet
#LinkedInMigration Unlikely
#YouTubeMigration Unlikely
#TumblrMigration: Avoided due to integration with #ActivityPub