Doesn't Google's ability to do that depend on the details of the old agreement? Does anyone know those details?
I could imagine an agreement along the following lines:
1. YouTube will show ads on all of creator's videos.
2. YouTube will pay creator based on some formula (in terms of ad revenue, plays, etc.).
Nothing in that would let YouTube (a) not show ads on the creator's videos or (b) pay the creator based on the hypothetical revenue the ad they didn't show would have earned. YouTube could try to get content owners to sign onto a new agreement that included that, but, um...