Just watched Vinny's stream of this, and I can't really figure out the ending. It seems like... you... skipped a step? I'm not sure how you got to the place in the ending cutscene from the place where you were before the cutscene started.
This is a valid criticism, although there is no missing step/teleportation/time skip. There are some elements in the background of the ending cinematic that are meant to better explain the relation between the two locations but I agree it can be somewhat obtuse to understand. Fortunately a logical understanding of the games locations in relation to each other is not needed for the story to emotionally function.