Before Marvel rebranded in the 60s, the company was known as Timely comics. During the Timely era, the publisher produced a host of quality superheroes, but the three top characters under their imprint were Captain America, the original Human Torch, and Namor: the Sub-Mariner. When Marvel got back into the Superhero game in 1961 with the invention of the Fantastic Four, the company wasted no time before re-introducing Namor into their mythos.
For comparison's sake, Captain America didn't make his silver age re-debut until Avengers #4, an entire year after Namor's reemergence. Considering how integral Captain America has become to the Marvel cinematic universe, one would imagine that Cap's Timely peer Namor would receive similar treatment on the silver screen.
In the clip from Black Panther: Wakanda Forever linked above, you can check out the first look at a character that coincidentally shares Namor's name but none of his characteristics. The character above has none of Namor's trademark arrogance and surly disposition. Instead, he's immediately complementary(to humans, no less) and uncharacteristically forthcoming about his past. Again, just a guy named Namor that doesn't share any of the character's key traits.
Oh well, the MCU is going to do MCU things.