I was a bit puzzled by Firebird (I thought that’s a fork of Thunderbird, like, say, LibreWolf or Waterfox), but I couldn’t quickly find the project, so my assumption is that it’s just the misprint, and author thinking of Fire-fox -> Fire-bird, not being into ecosystem for too long to remember the actual bird. Anyway, that’s irrelevant to the point author’s making, and I’m happy there’s a new Linux adopter now. Thanks, M$, I guess.