This might help. If Twitter for some reason decided to migrate to the Fediverse, then you could login to their mastodon.social account, follow @elonmusk@twitter

This might help. If Twitter for some reason decided to migrate to the Fediverse, then you could login to their mastodon.social account, follow @elonmusk@twitter.com, and reply to Elon's tweets, all without having a Twitter account. And Elon and other people on Twitter would see your reply (coming from, say, @taurusnoises@mastodon.social) and could reply to you.