I think these are two separate issues, the MCU has a large amount of “main” characters. Star Wars doesn’t necessarily, kind of like the comment above, it would be hard to find a time where Kylo Ren & Darth Vader are in the same place. I’ve gone into it before but, Disney wasn’t going to choose another era of the Star Wars timeline to display in their parks aside from the one they created. We could go on for days, but I think the main reason the marvel park additions are not in universe because it’s not that simple. There are currently 25 and counting entries to the MCU. Star Wars has the 9 movies, the clone wars, the mandalorian and now Bad Batch. Also this was probably the easiest way to make up different stories for different coasts without affecting the MCU timeline, unlike Star Wars, where they just duplicated galaxy’s edge on both coasts. I would also assume they won’t add any Star Wars anywhere else without it just being a carbon copy of Galaxy’s Edge.