I'm pretty sure this post is allowed, because its discussing the MCU. Also, there are slight spoilers for Spider-Man Across the Spider-Verse, but nothing major. Things I talk about are literally in the trailer or expanding on trivia for the first movie.
Anyway, I've posted thus question before, but since Across the Spider-Verse, it causes new complications. Is the MCU Earth-199999 or Earth-616? In this post, I present a few points of interest and my opinion. And I am overexplaining events, in case there's people who haven't seen specific movies
In this movie, they travel to Earth-838, the high-tech one. In this universe, where they are aware of the multiverse, the designate the MCU as Earth-616, which I believe is an out-of-universe Easter Egg.
In this movie, as well as in the trailer, we hear Miguel O'Hara say something like "don't get me started on Dr. Strange and the nerd from Earth-199999." (This is probably a misquote but you get the idea.) This is an obvious reference to NWH, and the MCU as a whole. Also, O'Hara has a lot more experience with the multiverse than 838 does.
In the Marvel Movies wiki, which I discovered yesterday, Earth-616 is the universe that Peter B. Parker hails from, which is the central universe in the comics. Also, Earth-65 is the designation for Spider-Gwen's universe in both the Spider-Verse movies and the comics. *slight spoiler time* This Gwen is the only Gwen Stacy who becomes a Spider-Man in the multiverse, which is the same in the comics. *end spoiler* I'm pretty sure that they actually took from the comic universes to make these movies, which I think is pretty cool tbh. This is my own conclusions, I'm sure there's plenty of analysis out there already that I haven't seen.
The MCU's designation is Earth-199999. Earth-838's designation can be put as an amateur mistake. Thanks for reading, I'm actually surprised I wrote this whole essay.