What's Canon?

For the purposes of any TTRPG campaigns that I run, the Star Wars universe follows Legends canon—the collective expanded universe established by various books and other media prior to 2014, rather than by Disney's Star Wars movies.

Specifically, my campaign settings use G-canon (George Lucas's original six movies), T-canon (TV shows prior to 2014), and C-canon (all licensed books, comics, and games from before 2014). Details and features from secondary canon (such as the Star Wars Holiday Special) and non-canon sources can inform the canon, as can details from the Disney movies, but these sources are not considered binding, and are superceded by G, T, and C-canon wherever there is disagreement (see Levels of Canon).

To the limited extent that it might matter to the setting, my campaigns also follow the theatrical releases of the original six movies, rather than the later re-released special editions. This means that, for example, "Han Shot First" when he killed Greedo in the Most Eisley cantina, and that the Sarlacc pit on Tatooine does not have a giant beak sticking out of it.

Additionally, where possible, all Star Wars TTRPG campaigns that I run or participate in are assumed to take place in the same shared timeline.

Who Owns Star Wars?

Not Disney, at least not the way I see it. Disney owns the legal rights to publish and sell new material for the franchise, but the fictional universe itself is larger than those legal restrictions. That isn't to say that I'm some sort of George Lucas purist either, though. I believe that most of the worst parts of Star Wars were the parts that George Lucas had the most control over, and that the original trilogy was good in spite of him rather than because of him, whereas the prequel trilogy was bad because of him rather than in spite of him. So then, what does make Star Wars good, and who owns it now?

Star Wars, more than any other science fiction universe I know of (and possibly more than any other fictional universe, period) draws from many types of sources made by many different people. Established Legends canon includes movies, TV shows, novels, encyclopedias, radio dramas, comics, role-playing games, video games, and more. Contributions to the canon have come from professional creators and authors as well as from amateurs and fans. While there are certainly more than a few contradictions and inconsistencies in the canon due to this type of construction, on the whole the Star Wars universe developed a relatively robust and self-consistent timeline without too much in the way of central authority. The fact that Star Wars now has multiple contradictory timelines and that any fan can more or less choose for themselves what aspects of Star Wars are canon, or add to the canon themselves, and have their decision be no less "correct" than George Lucas or Disney, is in my opinion one of the best things about Star Wars. No one owns Star Wars, which means everyone owns it. The stories that people might create together in a TTRPG campaign are just as valid to the setting as any others.