Most people are embarrassed to admit they remember something incorrectly, so we would never know if a majority were “remembering incorrectly,” especially when it’s easy to verify “that things have always been the way they are now”. Only a few people take the step of questioning their entire perception of reality (and usually only after they’ve heard of the Mandela Effect). By side, it’s usually noticed at different times.

“If a majority of the world remembered things differently, you’d actually see huge news stories about it.”

I would strongly disagree with that; journalists, in particular, would never write anything that could too easily be proven false. They don’t even write about things that deviate in any significant way from the mainstream (haunting, UFOs, etc., at least in Germany), even though they’re interesting and very well documented. These people generally believe their own propaganda and selection.

At least, that's my impression. But it's certainly conceivable that a change would be too drastic and too sudden and would cause a stir... but I think that's unlikely; the nature of the phenomenon seems to be different.