Judged from the writers’ demo. Same as you, I suppose?
Well,yeah,to an extent or another.
But,having listened to the said writers' demo as well,I can't help but feel that the song was,at least,80% already there,before Michael Jackson or Teddy Riley ever managed to "touch" it or consider its inclusion for the "Invincible" project.
This may also be coming from my personal bias,but,since the demo and the official version are so similar (nearly identical,which can only lead to me believing that Michael didn't contribute much,from a creative perspective,at least),then I can't help but prefer the writers' demo to Michael's cover/version.
He didn't bring anything new to it,in my view at least..(or should I get my ears checked lol?)
This wasn't like Michael,though,if you think about it.
Everytime he would record tracks written by others,he would still try to sound as close to the demo as possible while still adding his own "touch",here and there (for example,the changed ending to "She's out of my life";the falsetto that he added to "Human Nature";he gritty,signature ad-libs that him and Quincy put at the end of "Man in the mirror" etc).
But that is not the case for "Whatever Happens",actually (nor for most of the other Invincible tracks really,if you think about it..for example "Butterflies"). In that era he would simply cover the tracks as they were written,put his name on it and suggest that he was somehow involved in any part of the creative process..while that may have been impressively far from the actual truth..
(I'd still say that "Heaven Can Wait" is an exception to this though,as he at least inserted some of his signature screams/ad-libs at the very end of it,but still)