except you cannot, once its AGPL youre stuck with it

If you're the owner of the code, all the past versions of the project are and will be AGPL forever (or MIT, or BSD) but all the new versions will be whatever you want. You can also dual license. If someone forks the old AGPL version (or MIT, or BSD) they can keep that license on the fork, but they can't use your new code.

Yes, this is why so many projects have Contributor License Agreements - so the project owner can relicense at will.

It’s also why you shouldn’t sign a CLA if you disagree with that possibility.