NO SERIOUSLY... SPOILERS!!!
A big part of the movie is the introduction of the Illuminati, which is quite different from the comics in that it has Mordo instead of Strange, no Tony Stark, no Namor, and I guess the Lashana Lynch version of Captain Marvel instead of Black Panther. Oh, and Captain Carter who has nothing to do with the Illuminati in the comics (and was only just introduced very recently). So I think most of us assumed that the Illuminati was a group of characters from different dimensions but maybe this was just the Illuminati of that particular dimension, so the fact that most of them die in DRST2 made me wonder... if there is an overall all-encompassing version of the Illuminati that covers *all* the dimensions and not just whatever that one is, wouldn't they come after Doctor Strange since it was his negligence that brought Scarlet Witch to that dimension to kill its Illuminati? I feel like Doctor Strange is as responsible for those deaths as the ones at Kamar-Taj. So yeah, we could think of the death of the Illuminati characters as sad but there's a chance they exist in other places. The thing is... Doctor Strange didn't recognize Reed Richards of the Fantastic Four so there's a chance they don't exist in the MCU... yet. But I don't think we've seen the last of the Illuminati... maybe there'll be a MCU 616 specific version to come... (If I were Doctor Strange, I'd think "Hey, this is a pretty good idea" and do it if there isn't one in 616 yet)