I understood it to mean that this bird feels like this particular mammoth isn’t quite as comfortable but he has a lot of other mammoths to choose from, so he is free

Changing platforms will always somewhat inconvenient, as long as you have to rebuild your social graph else. This is maybe particularly the case on Mastodon, as you don't have a feed full of endorphin-maximizing content right off the bat.

Making the move to Mastodon does require a minimum amount of effort. I think it's good to be open about that. :)

What is comfortable is of course an individual consideration - personally I never felt comfortable on Twitter or Faceboook.
@sxan