Am I incorrect though in saying that what happened with Rogue One wasn't exactly normal? It's not like they just re-shot a few scenes; reports indicated that they had to reshoot as much as 40% of the film, rewrite key scenes, bring on a second director to supervise some of them, and hire a new composer because of the delays.
I'm not trying to make a mountain out of a molehill. I'm just acknowledging the molehill.
Everyone close to the movie has said that the 40% figure was bogus and that they wouldn't have even had time to redo that much of the movie that late and still have it finished on schedule (which would be true for a big effects movie like that). There were notable changes made to key scenes, but I think it was more about getting the tone of the movie perfect, which I think says more about Disney's dedication to getting it right, rather than the movie being a disaster beforehand. The change in composer was due to the reshoots being pushed back from the intended dates. Changing composer due to scheduling conflicts is also not that unusual. I don't know about a second director, but I did hear that the big ensemble cast was an additional logistical issue for the reshoots, so another director was likely a necessity of scheduling too.
Rogue One definitely could have been a very different movie in editing with some of the changes, but to call the situation a fiasco without us knowing all the inside details is imo a stretch. This business with the Han Solo movie suggest to me that maybe Disney is still trying to strike that right balance between giving the directors creative freedom to make a movie in that universe, and keeping a hold of the reins on what they want Star Wars to be at the top level.
Also, I remember reading about particular shots in the trailer that were never even intended for the movie, but just added to have some cool shots for that early trailer. I could probably dig up the article if I cared enough.