Late last week, just days before NBCUniversal tried to sell a roomful of advertisers on Versant, the company’s new name for its cable network spinout, CNBC reported that Warner Bros. Discovery C.E.O. David Zaslav was finally getting serious about his own, similar breakup—the parameters of which my partner Dylan Byers previewed last December. Now, as then, relegating these once very-profitable assets to their own bin of unappealing leftovers kind of makes sense. And while WBD and NBCU executives will be quick to argue that these moves will unlock growth at both halves of the former whole, the truth is that they set up the remaincos for success while leaving the spun-off assets to survive, or not, on their own and out of view.