My own thought process is that it's like Usenet or arXiv: The collective value of Github is so high that even if Microsoft loses interest, someone else will buy

My own thought process is that it's like Usenet or arXiv: The collective value of Github is so high that even if Microsoft loses interest, someone else will buy it from them or clone the content elsewhere. That said, I do wish there was an alternative that didn't involve a for-profit corporation.