As I understand it, detecting an adblocker is a form of fingerprinting. Fingerprinting like this is a privacy violation unless there is first a consent process.
The outcome of this will be that consent for the detecting will be added to the TOS or as a modal and failing to consent will give up access to the service. It won't change Youtube's behavior, I don't think. But it could result in users being able to opt out of the anti-adblock... just that it also might be opting out of all of YouTube when they do it.