This is interesting and probably makes sense/is plausible. Manfred is saying if enough owners are behind him he can pluck as many games into a national package as he wants. I think that would get heated if it meant taking away a lot more games from local rightsholder entirely (the current limit for national exclusive is 17, but Phillies and Yankees are expected to have 18 this year). But if he's just trying to use that to force all the inventory into MLB.TV without any blackouts (and with the league and clubs still being able to sell the local streaming packages) that seems more doable, and more easily negotiated (I.e. teams or league wouldn't have to pay big buyouts to end local deals entirely).
If you ask teams like the Phillies, Yankees and Cubs to give up their existing contracts for a truly national deal it seems like that would just recreate the revenue inequity, as they'd have to get a bigger share.
“Remember, we can take as many games as we want from any club in the national package with a majority vote of the clubs,” Manfred said last week. “I don’t necessarily need 30 (teams’ rights) wall-to-wall to get where I want.”
A copy of MLB’s constitution the league submitted in a court case in 2023 says that a majority owner vote is required for any league action related to video media rights. It also says a three-quarters vote is required for anything affecting revenue sharing “from any source.”