News about Mackie starring in a forthcoming 'Captain America 4' flick surfaced this week, with director Julius Onah reportedly attached to direct. This, of course, comes on the heels of Mackie's Disney+ show -- which ends with him accepting the CA shield.

You'd think that conclusion -- which was made very clear on the show, this after Evans' character, Steve Rogers, had already passed the torch at the end of 'Endgame' -- wouldn't be up for debate ... but apparently, among some fans, it is. And, THR alluded to that in a thread.

In response to uncertainty about Evans' possible involvement with the new movie and the character, CE himself weighed in Saturday ... writing, "Sam Wilson is Captain America."

The reason that's a big deal ... it seems to shut down trolls who, to this day, aren't cool with the idea of Mackie carrying on as the titular superhero -- a controversy that's been brewing since 2019 when he was officially tapped as Chris Evans' successor.

A lot of the pushback over AM has been straight-up racist ... with many saying a Black guy simply shouldn't be allowed to assume the role (even though that happens in the comics).

Now, Chris appears to be confirming he's done with 'Captain America,' and that Mackie will exclusively continue as the character ... without Chris's involvement going forward. Frankly, that makes sense logistically -- Evans is depicted as an old dude in the final 'Avengers' movie ... so to jam him into the plot, beyond just a cameo, feels unlikely/unnecessary.

BTW, Mackie as the new Captain America carries a lot of weight. It's revealed on the show -- based on an earlier comic series, which is canon -- that the fictionalized history behind Captain America is dark, with the U.S. government testing/perfecting the super serum giving him his powers on Black soldiers while Cap was under ice. So, technically, Captain America was built on the backs of Black people ... a metaphor to our own real-life history, some say.