Yes, but he didn’t snap Xander. They had the power stone and an elite military force, so there was a devastating battle, and then he slaughtered half the population the old fashioned way, as he was doing before getting all the stones - think of Gamora’s world. So presumably, there was no post-snap undoing.
And Disney can say the theme park stuff takes place outside of canon, and thus technically it does, but they’re sort of having their cake and eating it too - they went out of their way to bring Batuu into canon in Solo, and Cosmic is directed by the director of every Guardians movie with the full film cast. It’s canon in all but the most technical sense.
This isn’t a criticism, by the way, just a conversation. It probably would have been more visually interesting and narratively simple to theme the ride to Knowwhere - then we could get Cosmo the space dog, who is on the Skyway gondola anyway.