Doctor Strange in the Multiverse of Madness introduces us to the Illuminati, but the team might not necessarily be what you're expecting. While the prevailing theory has been that the group would be made up of heroes from a number of alternate realities (similar to the Guardians of the Multiverse), that doesn't prove to be the case after all.
Instead, Professor X, Master Mordo, Mister Fantastic, Captain Carter, Captain Marvel, and Black Bolt all hail from the same reality, a world where Doctor Strange seemingly made the ultimate sacrifice to defeat Thanos. The truth, however, is that Strange, a hero who helped form The Illuminati, started tapping into dark magic, causing an incursion that resulted in the destruction of another reality. We know the Time Variance Authority was established to prune Variants and protect the Sacred Timeline, but the MCU now appears to have established the rule that if a Variant remains on another world for too long, an incursion will occur, and when the two different realities collide, one will be destroyed.
After Thanos was stopped, The Illuminati came together and decided to kill Strange. He was accepting of his fate, and it appears the group has since been on the lookout for any of his Variants who might cause similar damage.
The Illuminati's world is a weird one. Slightly futuristic, its cities are lush and green, though everyone there is dressed in drab colours, making us wonder whether it's the happy world it appears on the surface. Clearly, the Avengers, X-Men, Fantastic Four, and Inhumans all exist in this reality, offering us a glimpse of just how much the MCU will change when mutants and Marvel's First Family make their respective presences felt. This group is part of the Baxter Foundation, not the Future Foundation, so we are curious how different the MCU's Fantastic Four will look. Oh, and those robots are indeed Ultron drones, but appear to have been created by Stark Industries (Tony Stark's plan to create an A.I. Iron Legion clearly worked in this reality).
By the time all is said and done, The Illuminati is very much dead. However, introducing the idea of incursions is significant. In the comic books, a new version of The Illuminati was formed to protect the main Marvel Universe from being destroyed during the incursions taking place across the Multiverse. With the number of those increasing, countless realities are eventually destroyed, and Earth was reformed as "Battleworld," a reality made up of several different worlds ruled over by Doctor Doom. This all played out in Secret Wars, and ultimately served to combine the regular and Ultimate Marvel Universes, bringing Miles Morales into the former along with a handful of heroes and villains from other worlds like Spider-Gwen and The Maker.
Clearly, this is what Marvel Studios is now building towards. A Secret Wars movie could create a new Marvel Cinematic Universe where the X-Men have always been around, opening the door to Wolverine having been part of this world's history for decades rather than just showing up now out of the blue. It could also mean that certain key characters are re-cast, potentially meaning we haven't seen the last of Iron Man, for example. We don't know how long all this will take, of course, but Kang the Conqueror playing a major role seems a given.
Things are about to get crazy, so buckle in, folks...