Making Star Wars, a reliable source of Star Wars production news, claims that when they asked a few crew members what was being reshot, they laughed and said “everything”.
‘It was not Edwards’ fault as McQuarrie’s draft wasn’t completed when much of the film was shot and revisions kept coming in that made the film feel uneven.’
This is all ultimately good news though, and the studios are clearly committed to making sure the film is the best it can be, even if it comes at great expense.
Reshoots are commonplace for big budget, big expectation movies like this, but are rarely this extensive.