Namor's Arrival Was Teased All The Way Back in Endgame
Even though Avengers: Endgame's writers denied any references to Namor, fans are sure one scene in the movie was an Easter Egg hinting at the Sub-Mariner joining the MCU.
The scene in question features a meeting of the Avengers who have survived The Blip.
Okoye, Rocket Raccoon, Nebula, War Machine, Captain Marvel, and Black Widow meet via telepresence. Natasha Romanoff, who has become the leader of the Avengers, holds the discussion of current issues the superheroes face.
During the discussion, a question of potentially harmful tremors near Africa is raised. Natasha asks Okoye how Wakandans are handling the earthquake and gets the following reply: "It's an earthquake under the ocean. We handle it by not handling it."
Sounds like a clear allusion to the certain underwater kingdom, right? That's what the MCU fans have been saying since Endgame was released.
Now that one of the oldest superheroes from Marvel Comics finally entered the MCU via Black Panther 2, the theory sounds much more plausible. But why did the writers of Endgame deny that this scene was meant to be a nod to Namor?
First of all, Marvel Studios is pretty secretive about new characters joining the MCU. Being a big deal for long-term Marvel fans, Namor entering the MCU was kept quiet for several years.
When Tenoch Huerta joined the cast of Black Panther: Wakanda Forever two years ago, his role was not released and remained a mystery right up to the movie premiere. Then, there is a legal issue with Universal Studios, who purchased the rights to the Sub-Mariner in the late 90s when they planned to make a standalone movie about Namor.
Marvel managed to obtain the rights to the character back, but Universal still holds the rights for the distribution of any Namor's own movie. This could actually stop the Sub-Mariner from having a solo spinoff unless the studios come to terms and agree to some kind of collaboration, just like they did with The Incredible Hulk.
That said, Endgame was probably not the first Marvel movie to tease Namor's appearance. In Iron Man 2, fans first spotted the reference to Wakanda.
The country was marked on a map hanging in a S.H.I.E.L.D. office. But also on a map is another mark put in the middle of the Atlantic Ocean, not far from Wakanda. Though it might be not a direct hint at the Sub-Mariner's entrance, it definitely set up Namor's existence in the MCU.