For most big-company CLAs, when you sign the CLA you either give up copyright of your contribution or you explicitly provide an irrevocable license to the targe

For most big-company CLAs, when you sign the CLA you either give up copyright of your contribution or you explicitly provide an irrevocable license to the target to use your contribution in any way they want, depending on the precise wording of the CLA. (The latter is more common these days.) In either case, you don't get to complain if your contribution is relicensed later. And no, it doesn't matter what the new license is.