Hey guys. Writer from Star Wars News Net over here.
Recently, that Page Six report about Rogue One: A Star Wars Story being a mess and requiring reshoots left a bit of a splash across the internet.
I have it on good authority that there's not actually a cause for alarm. The concerns were sensationalized for the purpose of selling an exclusive story; the three to four weeks of reshoots and pick-ups were planned to begin with, and the cast knew about them well in advance (as evident by Donnie Yen's recent statement).
I know that Star Wars: The Force Awakens had reshoots that took the same amount of time. If we were dealing with a messy production, then the reshoots would last a lot longer than a little under a month. Fant4stic, for frame of reference, had reshoots that lasted 5 months.
With any tentpole like this, this is becoming the rule and not the exception. So don't panic.