Unpopular opinion here:
For the most part, i do not want the rights going to disney.
The Spiderman movies made by Sony, the ones made by Sam Raimi, were for the most part good, the Amazing ones were not "amazing" at all (except that Green Goblin/Gwen Stacy scene, that was awesome) and Homecoming was the worst Spiderman movie of them all (and the sequel does not look much better)
The Fantastic Four movies were not good (The one with the Silver Surfer had its moments) and they were just like an mcu movie, if they were part of it they would have been praised, but in this case i do want them to be part of the mcu, the Human Torch and The Thing have the personality of "witty quips" that disney likes so much in Marvel, but they will probably go overboard with the humor sadly.
Now, the X-Men franchise, THAT is the one that i dont want nowhere near disney/Marvel.
All of the movies from that saga have been from good to awesome (okay the Wolverine trilogy was not very good, but whatever) and i highly doubt that we are gonna get actual good X-Men movies from the mcu, the reason being that what makes the X-Men movies good is the tone, it is serious, dramatic, tragic, and the mcu does not dare to go "full Marvel" yet, they always have to put some out of place joke or dissapointing villains or third act.
They are never gonna make something like X2 or DOFP.
Even Infinity War, the best mcu movie and a pretty good movie overall, struggled between serious and "fun" at times, and the quality of the mcu overall has been pretty inconsistent: we can get a Winter Soldier, an Infinity War, or we can get a Thor Ragnarok or an Iron Man 3, is pretty random.
I dont get at all that mentality of "any superhero/marvel movie that is not part of the mcu is bad", that is not true at all, there are even people wanting Dark Phoenix to bomb at the box office or not even released at all, and say that is gonna be an awful movie already (and some people say that Apocalypse is a bad movie, i mean WTF is literally a comic book movie)
I am gonna put a quick example and then end this already endless wall of text: Doctor Strange is an awesome movie, really good Marvel story, however it has a lot of jokes that are 100% out of place and do not fit with the tone of the movie at all, is like after reading the finished script a producer came and said "that is nice, now put some jokes here here and there".
Because of that the movie does not reach the quality it should, the jokes are so bad and so forced and used to kill the tension the serious moments or the characters, that bring the whole movie down.
And this happens in pretty much every mcu movie, and it never happened in the X-Men movies (that i can remember).
Short version: If the mcu can fix its tonal inconsistencies, i would love to see all characters in the mcu, it would be mind blowing to have a group shot like in comic books with 50 characters and all the stories happening in the same place, but as it stands today, no thanks.
We got BP and IW that they were good serious movies and even those had some awfully out of place jokes shoe horned in them, and then Antman and the Wasp which was just embarrasing, and Captain Marvel and Avengers Endgame look good, they look serious, but i cannot help but fear that at some point they are gonna have a "invisible Drax" kind of bad forced joke in there at some point.
If the mcu can stop going overboard with the humor, it really would be best for everyone, the audience and the quality of the movies themselves.
/Rant