Would his deterioration into a visual freak have happened in the present-day 24-hour news cycle/reality TV atmosphere?
Short answer: no. Obviously not. He would have been too exposed. He would not have had the ability to basically isolate himself and go crazy. The world of Twitter/Facebook/YouTube would be able to somehow make Mike into a saner person.
This line of thought led to another, more over-arching theory. Of course we all know MJ was famous almost from his birth. He was constantly exposed and constantly under the microscope (at least as much of a microscope that there was in the 70s). But he didn't attain his remarkable heights until the 80s. And then went even higher in the 90s and 00s. So here's the theory:
Michael Jackson was the unfortunate victim of the mass media transition.
I look back at photos of Michael in the 80s. I specifically do it to see if I could pinpoint when he started to change and become white. Surprisingly, there aren't that many photos/videos available other than what was closely monitored by him. No way in hell would this have happened 10-15 years later.
Mike blew up at a time when sharing his personal information with the world wasn't mandated by the status quo. Celebrities still had some measure of privacy. Not because there was some sort of respect that fans paid their idols, but because technology was just not there yet. At some point in the late 80s and early 90s, the media tide started to shift. But Mike stayed put, growing more and more isolated and... well.. just plain freakish.
We started demanding reality from our celebrities. You can trace it back to gangsta rap and the Real World. Little by little the up-and-coming stars shared more and more. Mike did not. As the 90s went on, while celebrities weren't the most sensical people, their celebrity caused them to view themselves as their fans did. MJ got a pass. He got grandfathered in. Once he caught up, in the early 00s, and tried to share his world with ours, what resulted was disastrous. He was already too far over the edge. What he thought was normal was actually not.
Who knows what would have happened if he reached his stratosphere at a time when he couldn't isolate himself that easily. What if he spent his time between albums judging American Idol or exposing himself more through the readily available media outlets instead of going away and coming back with a lighter hue and a slimmer nose. If anything, it's interesting to wonder.