The biggest moment of Doctor Strange 2 trailer occurs when Strange is handcuffed and escorted into a room by what looks like upgraded versions of Ultron and a mysterious voice occurs.
"We should tell him the truth"
The voice resembled to Patrick Stewart's Charles Xavier or Professor X from X-Men franchise, and we also see sight of his half bald head hinting to MCU's "The Illuminati" and this team may hold the key to the future of the MCU.
Tom Cruise Rumor Backed By Illuminati
The Illuminati's consists of Strange, Xavier, Iron Man, Namor the Sub-Mariner, the Inhuman king Black Bolt, and Mr. Fantastic. Illuminati was founded by Tony Stark, and that's why Tom Cruise Iron Man rumors are so heavy.
How Is It All Connected?
The Illuminati were responsible for kicking off a number of Marvel events, including the decision to launch Bruce Banner into space after one of the Hulk's rampages leveled Las Vegas.
The Unexplained Is Their Deed
Just like sending Hulk to planet Sakaar where he becomes a gladiator and later faces Thor in Thor: Ragnarok. There have been many unexplained events that will open up in "The Illuminati" as their doing.
In A Nutshell
MCU's Illuminati is a group of most powerful or insightful put together in order to deal with major threat after Skrull Invasion. But just like the real world Illuminati, it goes corrupt and results in Civil War, Secret Wars and World War Hulk.