Marvel shouldn't get the rights back. I shudder to think what would happen if they got their hands on Spidey and the X-Men. We will soon see them work their Rumpelstiltskin act on GotG and Ant-Man by turning those minnow franchises into whales, so do I even dare ask what they could do with giants like Spidey and X-Men? I can only imagine that people would deem those films the greatest of all time if they were shepherded by that studio.
The tidal wave of love and downright awesomeness would have the potential to destroy coastlines in mere seconds....
In all seriousness, there simply wouldn't be enough theaters on the planet to satisfy the mass hysteria that the Marvel/Disney marketing machine™
would no doubt create. That great frustration alone would inevitably make people's minds implode. Eventually it would turn them into parasites and they would devour the flesh of their fellow man, woman and child. No thanks to that says this citizen of the world. Keep Spider-Man and the X-Men at their respective studios and let mankind continue on with its struggle. Icarus is a great example that we should not get too close to the sun.
There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy