GitHub is losing money but that doesn't mean GitLab and BitBucket are profitable. BitBucket is part of a larger organization so it really doesn't matter if it loses money. As for GitLab I can't find anything but by 2019 they're expecting SaaS to be the majority of the way they make money (which is identical to GitHub) so I'm not sure why you expect the incumbent to fail and the underdog to succeed with identical business models.
Sure it's possible but I don't get it. Don't forget as more of these OSS projects take advantage of GitLab's free repositories the more money GitLab will lose.
source on that claim? If I remember right, the last numbers I published (from some bloomberg article last year) showed them spending a lot, but profitable.
I'm just waiting for GitHub to be bought up by MS and turn into Sourceforge 2.0.