Thematically speaking, it makes plenty of sense for Ryan Coogler to want to echo a moment from the original Iron Man.
The story of the first Marvel movie stands as a watershed moment in the MCU’s history because it introduces Tony Stark to the world of superheroes and lays the initial groundwork for The Avengers Initiative.
In a similar sense, the ending of Black Panther brings Wakanda into the spotlight and implies a fundamental change in the landscape of this franchise that will have huge implications going forward.
Beyond that, for the first MCU movie, and the last movie before the release of Avengers: Infinity War to feature press conferences in their final moments also seems like a poetic way to bookend ten years of Marvel films.