Yeah, sorry if my terminology was unclear here: by “relicense” I colloquially meant to say “assign a different license to the project that is applicable for any work from that point onwards”.

> Any previous licenses used (MIT here) bear no effect whatsoever. There is no license in the world (and cannot be) that would prohibit the copyright owner from changing it.

I don’t think it’s that simple. The Bear project appears to have accepted external contributions under the original license, so the project is subject to that license as long as those contributions remain.

It may not be a big practical issue in this case, due to the MIT license being quite permissive, but if the project was e.g. GPL-licensed, the maintainer wouldn’t trivially be able to change the license in “whatever direction they want”. (And by “trivial” I mean without e.g. rewriting or discarding the external contributions.)