Just back up the data somewhere else. No matter what you use, there's a possibility that your stuff will just vanish one day. Your own hard drives could die, your building could burn to the ground. Don't put your data into something that you can't get it back out of later. Off site backups are like sysadmin 101. You even need to back up your cloud infrastructure, it's not unheard of for any of the cloud providers to lose a whole bunch of VMs, storage, etc all at once. It's rare, but it does happen, just like an account lock-out.

The problem isn't just the data, it's the access. You can point a domain of your own at a different server if the old server vanishes for some reason, and retain interaction with your users.

But if GitHub bans you, good luck with that. They're not just deleting your data; they are removing you from your own community, because they control its environment.

Edit: And the domain name system, unlike services like GitHub, actually has processes and mechanisms in place for recovering access and filing disputes.

I have backups, but it's more than just data. GitHub is a platform for collaboration, and should the plug get pulled from the platform, collaboration stops and data living outside of the repositories is lost. I can't afford that down time.

And you can still mirror to GH to benefit from the extra visibility and attention this is bringing to your project.