Pay content creators who don't participate and are on monetised accounts as if the Red views had been seeing adverts, show adverts to everyone else.
I'd extract money from the red customers for the no advert feature, who would be more invested in the feature because their favourite channels would be on it. The Red customers would extract value from viewing that user's content. I'd still be getting paid for the adverts seen by everyone else. The content creator would still getting paid.
I honestly don't see any loser in that besides the content creator maybe not getting as big a cut as they would have if they chose to take the deal. If the Red deal was better than the ad-content deal then I'd be better off treating creators that way and letting them opt-out.