Take one example, David Bowie's voice changed over his career. Never once would you question who was singing. Elton John's changed very much from the late 80's onwards. Again, it's always unmistakable when he sings.
Michael Jackson had a more distinctive voice than BOTH of them, and we are supposed to believe that he sounded different for a while because of some PVC piping or whatever? Wool over eyes, hands over ears syndrome. It's clear whoever thinks Michael Jackson is singing these songs will not change their minds because of a post they read on MJJC, but the burden of proof lies with the case that it is him singing. The reasons for this being the case have all been, quite simply, laughable and far fetched.
I'm also certain we will all be kept in this loop of never ending re-occurring threads until we die. Its an embarrassment. An absolute embarrassment. You wont find threads like this on a Prince, Bowie, Whitney or Freddie forum.