I don’t know why some people think had Michael spoken about vitiligo (earlier), it would change anything to the situation.
Firstly, it’s his business. Let the man have some privacy.
Secondly, call me pessimistic or whatever (which I don’t think I am), but I don’t think he would be less perceived as a “*****” or “weird” by some people if he did say he had said he has vitiligo earlier.
I remember stories about regular people who have vitiligo, from nowadays and 15+ years ago, who have never concealed the fact about having vitiligo. And, basically, they had/ have been treated like they should be in quarantine by some people (being made fun of, people blatantly staying away from them, people wouldn’t touch what they touch, etc.).
I don’t think a celebrity would have a much better experience with vitiligo than these people, considering that the celebrity is more exposed to the public eye.
Not to mention that, by 1985 (and maybe some years earlier), Michael was already perceived as a “weirdo” by some people (tabloids, but not only them). And his skin was still (fully) black.
I remember showing to a girl, in class, a photo of Michael where vitiligo is quite noticeable :
While acknowledging the vitiligo, her reaction was not compassionate at all : “yuk”. Note that the girl was not some ignorant teen : she was in her twenties.
Some people can be unnecessary judgmental jerks, sometimes.
Thankfully, not everyone is a judgemental, which leads me to the third point :
In spite of that, Michael was/is still one of the most popular and most loved persons ever.
Every time Michael made an appearance, whether it was at a concert, at a TV show or in the streets, people WANTED to be near him, to tell him how much they LOVED him. Some even wanted to hug him. Everywhere, on every continent, Africa and America included.
https://youtu.be/8pshi2nWlv0
https://youtu.be/AoupR2HUQJo
https://youtu.be/mvgTmgHwkSc
https://youtu.be/UeFUvW5YInQ
Not even Madonna has been so revered.
So, to me, the situation would not have changed much, imo. Some people would still find any reason to not like Michael, others would still love him.