I figure with the flag is was probably a placeholder for an unfinished shot.

I think all the other changes are bs but I think the credits extension is probably legit. I saw the film in theaters quite a few times and knew the end credit suite pretty well and I never noticed a difference (and at least one difference between those two is obvious - the inclusion of Scherzo for X-Wings). Not to mention the smoking gun (which no one seems to mention) is the FYC end credit suite. All the FYC tracks contain the music as heard in the film, edits and all. The FYC end credit suite is longer than the OST one as it’s been edited to include the concert version of March of the Resistance. So why else would the FYC have that edit and not the Rey’s Theme and Scherzo for X-Wings edits present on the Blu-ray?