I looked it up, Luna Snow is a recent creation, and a diversity insert. It isn't clear in the trailer, but she's Korean, and the character is written by Koreans or Korean-Americans...in 2018. Also, the character is a freaking K-pop idol. Yeah.

She was first created for...a mobile game. Created especially to be "culturally diverse." Their words.

From Wikipedia: Marvel Games Executive Creative Director Bill Rosemann commented on her debut, "Marvel has the greatest fans around the world, and they deserve heroes that they can not only cheer on as they fight evil, but also connect with on a personal level."

And apparently you can only connect with someone you share a skin color with. Again, based on their words.

So it's not so much that the female roster is weak, it's that the suitably nonwhite (and aliens/mutants don't count; it has to be a human and any race except white) female roster wasn't woke enough for their tastes so they went with a recent addition. Should have just gone with Psylocke who is, well, complicated, but sort of nonwhite. And just badass.

So, yeah, no Psylocke, or any other existing characters. We get K-pop idol diversity insert mobile game character.