LÖVE

In June 1, BitBucket will remove all Mercurial repositories.

Is LÖVE going to switch to git? Is it going to move to a different hosting? Both?

Already happened iirc, just the issue tracker needs migrating: https://github.com/love2d/love/commits/master

Oh so that isn't just a mirror?

I was hoping it would be to GitLab or OSDN...

It might be? At least it was previously, but now i honestly don't know; i do recall some talk about it being the new primary repo though... still, slime can probably correct any misinfo about this. :v
(This commit might be somewhat telling though: https://github.com/love2d/love/commit/2 ... 9d2fe4f0f9 )

It was a read-only mirror for a few months until we moved the build system repositories and release binaries over - now it's the main repository, and the only things left to move are the issues.

Since we already needed to change things thanks to Bitbucket's decision, moving to Github at the same time made sense to me because it has a superior ecosystem and some other quality-of-life features (for example code is actually browsable in the mobile version of its site, whereas that's completely broken in Bitbucket).

Now that we've switched from hg to git it will be fairly trivial to switch platforms to another git hosting service in the future if we need, but I don't expect that will happen unless something drastically changes with github like it did with bitbucket.