The Dawn of the Jedi?
We get to see Mae confront a robed figure—it’s possible that it’s the short-haired Jedi who may or may not be Sol—on an ocean-covered planet. The environment they’re in looks a lot like it could quite possibly be Ahch-To, the site of the first Jedi Temple and the home of Luke Skywalker in exile during the events of The Last Jedi. We know very little about Ahch-To’s place in the Order by the time of the High Republic, but whether or not this is indeed that world (all we really know is that the planet’s location as the original site of the first Jedi Temple was lost to common knowledge by the time of the Skywalker Saga), this seems like a very important location.
