Well, this is the fundamental problem of trusting private companies to build, maintain, and run public infrastructure, or at least, infrastructure which is treated as de facto public. They do in fact own it, and, being a private business, they are in fact going to respond more to mob upsets and strong-arming than to any kind of liberal (in the classical sense) principle.

If you wanted some liberal principle, there's an organization lying neglected in the corner whose charter says it more-or-less cannot censor anything under any circumstances. Or you could start it as a commons trust, or a users' cooperative, or some other form of organization that would ultimately leave your source repo company more accountable to its users than to baying mobs of internet raiders trying to threaten ad revenue with bad publicity.