Michaels weight has been discussed before and someone mentioned that together with propofol you give ephedrine for the bloodpressure.Ephedrine is also taken by persons who want to lose weight and Murray probably gave to much of it.
I think Murray had to tell Michael about it , maybe that´s the reason that Murray started to give other drugs than propofol and maybe Michael started to gain weight again even if it was so little so you couldn´t see it.
I think Michael didn´t want them to think he couldn´t do the shows because he seemed to became to frail and skinny, when there was something he could fix.
Earthsong was the last song he did on 24th after hours of rehearsals and for me he didn´t seem tired.
we can also see thriller from 24th and I can´t see he was unhappy there.
I remembered from Raffles(?) interview with Travis Payne that Michael said he wanted lady Gaga to be one of many gueststars and she told after his death that he wanted her to open his shows.