Sorry, for my late response. I had a power cut and when it came back, ended up dancing for 2 and a half more hours than what I said tehe.
Anyway....
Basically everything you said is insanely accurate.
Only two errors were, I think you think red jacket day was a rehearsal. I'm pretty certain he didnt rehearse that day. Its the footage you see of michael before thriller starts where they're making and directing the vignette. So the footage did make it in but, comparing it to a lot of photos, he looked at least 25% more skinnier in them than the video so those two angles of michael in the movie were likely the ones that didnt make him seem TOO thin. The other thing is that those photos were also released by AEG and/Sony, So that means michael actually looked even skinnier than that if they chose to release them. So yeah, if red jacket was including in this hypothetical doc, it wouldn't be very much of it at all and probably just include extended scenes of what we saw of michael sitting and directing and basically the minimum amount of footage theyd need to show of that day to cover thriller. In terms of those 4 days he was at sony studios (where red jacket was), theyd probably focus on including a lot of the black shirt day, which he also went to rehearsals afterwards too cause we see him perform smooth criminal on the stage and yeah, clearly he obviously rehearsed that day so an even better excuse for them to skim over red jacket and just show off most black shirt.
Second error was when it became obvious michael we unwell. Michael only started using propofol every night, on april 22nd (yes, I just did math to get the exact date) and as we see in the TWYMMF band rehearsal type thing in the movie, which would've been mid-late may, michael was pretty healthy seeming and looking. Like he even looked a decent weight there, take note of his legs next time you watch it. Seemed a little out of it, but definitely not too messed up to be able to do the work, as we saw. It was between the 9th of june to the friday before his death that it became clear there was something extremely wrong with him health wise.
Im not going to talk about the quite extreme underweight in early june (red jacket) because, michael always wanted to be skinny. And his skinniness wasnt really an issue they seemed to need to be worried about especially cause michael had a 24 hr doctor who should of known if the weight was having too much of a negative effect on his body to where it was TOO dangerous. But yeah.
Those were literally just me nitpicking, I thought I might as well because from my experience this week, I feel you might actually appreciate the information that comes with the nitpicking sooooo.... HAHA
But yeah, literally your whole thought on this hypothetical doc is entirely correct and accurate to what would happen regarding it