Has Star Wars ever used the concepts of time travel and parallel universes before? I know there have been some What If?-type stories, Star Wars Infinities or something, exploring hypothetical alternate outcomes of the movies, but were those intended as events that "actually" happened in other branches of the multiverse or just as "imaginary stories"?
The Wookieepedia article on time travel is here
It's surprising how rarely SW has done anything involving time travel, since it's usually such a staple of the genre.
And they don't seem to have done anything with alternate/parallel timelines per se. All the Infinities
-type stuff seems to be presented merely as "imaginary stories." So it doesn't seem there's any precedent for the idea of the extant EU being declared a "real" parallel branch of the multiverse.