This war has pretty much spanned 3 generations of Skywalkers. If you haven’t lost someone by now consider that a miracle. No, fan theories didn’t ruin what happened to this or any other character, it was a director and writer who made a movie that goes in circles. At the end of this movie we were no more ahead in plot or character development than we were at the end of Force Awakens. We left them running from the first order, same as TFA.