Agree that we need more info. But skeptical on the prospect of a mass migration opportunity. It's highly unlikely Barcelona will provide account migration functionality. Theirs is a business model of enclosure and extraction, with zero incentive to provide captured users a means of escape.
Also suggest checking out this blog post by https://social.coop/@J12t , which speculates on a partial, extractive ingest-only federation. Considering the stakes and who we're talking about, it's not unwarranted to consider worst-case scenarios