What if he hadn’t been given the injections that subsequently killed him and was able to do that massive tour

The releasing of the album isn't the problem, it's him being able to perform the 50 concerts. Performing has always been exhausting for MJ, you'll notice in the 90s he gains some weight before embarking on a tour because the performances make him lose 3-5lbs a day. He was so so thin here and Idk if he would've been able to perform all the shows.