The Alternate Continuity the ride takes place in is in one of the Alternate Timelines created in Avengers: Endgame.
Word of God renders the ride non-canon to the official MCU, but that's probably only in regards to the events of the prime timeline. If it does occur in one of them, it's likely the byproduct of a "butterfly effect" from one of the small changes made by the Avengers' actions though it most likely can't be the one where Nebula and Rhodey borrow the Power Stone since that timeline's version of Gamora is now in the main timeline. Alternatively, the ride could also simply be set in one that was already existing separately.- With the events of Loki, it's safe to assume this continuity is one of many branching off of the Sacred Timeline.
