Campaigns / officials have used multiple services in the past to reach the widest possible audience.
Likely, those involved with the POTUS arriving on threads know little about the difference between mastodon and Threads and how (and if) they communicate.
The core problem of validating government officials identities is not solved by threads since you cannot bring a domain to threads.
So really this kinda seems like a big ol' Nothing Burger, unless you're a threads user :cirno_shrug: Even saying 'the fediverse is FORCED' is hyperbolic. His ass wasn't here before, and huge swaths of the fediverse aren't American.