GitLab too, but granted, if you host your own version, you wouldn't lose anything.
That being said, GitHub has almost no choice to keep being a good guy with the OSS community. If they lose it, they lose the respect of the developers, and they would lose their paid customers in the process.
Another point for Gitlab is that it can be forked if the parent company goes bad (e.g libreoffice and oracle). When looking at it with this perspective, widely-used essential projects can live and thrive from one party to the next.
