Long term who knows how successful any cable network will be, but right now the NBCU cable networks part of the spin-off are profitable with billions in revenue, so shutting them down doesn't really make a lot of sense. Not to mention, shutting everything down and moving all the shows to the currently unprofitable peacock just increases expenses for peacock. If a show is successful on E! or Oxygen, it makes sense to keep the show on that network and have that network cover the majority of the costs instead of shifting the cost of the show exclusively to peacock where the show might not even perform as well. Same goes for moving Bravo shows exclusively to peacock. It makes more sense for NBC to keep Bravo and have the profitable network finance shows which can then perform well on peacock, and peacock doesn't have to cover the majority of the costs.
I don't see how it makes sense for MSNBC & CNBC to merge into one channel. Both networks are highly profitable on their own and target different audiences. Besides weekend marathons of Lockup, left wing opinion programming is the only thing MSNBC has had success with. While I as a news junkie like them to cover news, I accept that there are so many news channels out there covering news, and MSNBC is the 2nd most watched news channel because it focuses on left wing opinion. Whenever they do focus on non-political news their ratings fall behind CNN, I still think they need to cover non-political news as a news channel and I'm disappointed with their lack of coverage for major international news stories over the past few years, but it's hard to deny how successful they have become focusing on politics with the left leaning view.