It didn't seem to be given any extra context in the two sequels; A man is struck down by Kylo and he's standing with the Knights of Ren in a rainy, rocky landscape with a few other bodies around. While some think this depicts Luke's academy and students being killed, the character doesn't seem to have a lightsaber but some sort of staff, and a helmet. The helmet kind of resembles the training helmets seen in AOTC, but also the deleted character (Who got an action figure in the first wave for some reason) Constable Zuvio. I guess it can be just a random scene of Kylo and the Knights doing their galaxy-conquering thing.
Then again the vision might not have meant to show a real event, as we also see Kylo Ren in the forest at Starkiller base (definetly because there's snow so it can't be their confrontation in the sunny green Takandona forest that happens shortly thereafter) at the end but he's wearing the full helmet, which he didn't in the movie.
Although unintentional probably, Ren in the visions reacting to Rey's presence does seem to slightly foreshadow their connections in TLJ and ROS.