How was that a twist? If you seen like 10 movies in your whole life, you'd know from the 1st scene who the bad guy is. I don't even know Iron Man comics or the character and I knew who the bad guy was after the first scene of the movie.
Killian being a villain wasn't a twist. Im pretty sure anyone woth half a brain-cell knew that he would turn out to be a baddie. I mean, the dude is called "Aldrich Killian", being evil might as well have been on the guy's birth certificate. The twist I was referring to, was The Mandarin being fake. I expected Killian and The Mandarin to maybe be in kahoots or something, but I never in a million years expected The Mandarin to be a complete fabrication, especially not as goofy as it was.
Also come to think of it, Agents of Shield did a whole Darkhold storyline. I guess WandaVision just renders AoS noncanon?
The canonicity of the MCU's shows outside of D+ has been in question, in my mind, for a while.
I mean, Mahershala Ali who played Cottonmouth in the Luke Cage series is now going to be playing Blade, and that is going to be a completely new character in the MCU, so that indicates that maybe Netflix's Luke Cage isn't canon. But, things get a little shaky when you consider that Netflix's Daredevil is rumoured to show up in Spider-Man 3 (alongside seemingly everybody else). So what is canon, and what isn't?
Officially, the current stance AFAIK is it is canon, but I wouldn't be surprised if most of it was swept under the rug later on down the line, retconned, or replaced with some kind of multiverse shenanigans.