It is highly unlikely that AEG will release more ‘This Is It’ footage in the future.
This makes sense because what has already been released is the decent (but through heavy edit) part of the rehearsals. The rest of it, is simply unwatchable & too painful for his fans to watch.
About the Botox (cosmetic) injections, Arnold Klein (his longtime personal dermatologist) revealed among other things (in a lengthy interview after MJ’s death) also the following:
MJ asked from him to make his face as perfect as possible (for those upcoming shows) because he wanted his female fans (that would attend those shows) to have orgasm just by watching his face (while he was performing).
But, it seemed MJ overdid it with the Botox (cosmetic) injections at that time, thus side effects from them began also to contribute to damaging even more his physical condition while he was preparing for his comeback.
He was fully drugged up right before in order for him to appear at that O2 press conference.
The way, for example, he giggles all the time in that silly way while speaking, is just one of the strong indicators of the effects of drugs on him during that brief speech.