But it isn't something that could maybe happen.
Obviously we can't expect everyone who joins the conversation here to know everything about everything by default, but I think it's fair to ask that people familiarize themselves with the basic foundational facts of what's being discussed before constantly weighing in.
In this case, it's been discussed at length over many years that Disney can't just be "annoying" to work with. They have to, through Marvel, deal with Universal in good faith. Otherwise, we wouldn't see major, advertised enhancements like the redone Hulk, the redone Spider-Man, or the refreshed character costumes (granted, that was long ago at this point, but if I'm not mistaken it was post-Disney acquisition). In turn, Universal has to maintain certain show standards and keep their presentation of the characters consistent with the Marvel brand. But Disney can't just decide to be petty and refuse to approve whatever Universal throws at them - that would be a breach of contract, and it would likely lead to litigation (or arbitration, if that's what's specified).
It would never be as simple as Universal going "oh hey, Disney's so frustrating to work with this on this, let's just give up these rights that are worth billions of dollars." They would attempt to enforce their contractual rights, and likely prevail.