MS are a bit stinky, but I'm not moving off GitHub preemptively. They can prove themselves to be decent or bad custodians of the platform, and git repos are inherently decentralised anyway. When the time comes, I can always jump (and so can you, and that makes the time less likely to come).
@derwinmcgeary GitLab is working on being federated: https://gitlab.com/gitlab-org/gitlab-ee/issues/4517
GitLab is great though, and FediVerse Git would be enough carrot even though MS GitHub isn't enough stick on its own.