Psylocke isn't Cultural appropriation. She's much worse. She's colonialism and racial theft.
Basically, they took the Asian woman, killed her off, and let Psylocke run around in her body, acting like a fake Japanese Psychic Asian Ninja Chick while Ignoring much of her UK/English Heritage.
Now you can be Asian and from the UK, that would have been the best route. But they then tried to retcon her into being Eurasian a 50/50 mix of the two women. So she sometimes looks Asian and sometimes not.
The problem comes in with Ignoring her family, and UK heritage, and having her being shown fully adopting Asian tropes in images, and in the books. So let's kill off the Asian woman so the white woman can exist as "representation" of a person of color. Let's not have an actual person of color be the person of color.
She doesn't even mention her niece. They did everything they could to remove her from Captain Britains lief and mentions. It's ridiculous. The best thing to do is bring back both women in their bodies, and share teams.
As a huge fan of Psylocke. Anyone who thinks this Psylocke can take Cap in a Hand to Hand situation is crazy. Hell in the Comics, Cap would curb stomp. I think some of you have a hyper inflated view of Ninjas. a Good Boxer can take a weaponless Ninja. A good way to measure fighting skills is to look at MMA. That's a MUCH more realistic battle than choreographed fighting.
Cap is Strength, durability, agility, cunning, Finesse, tactics, and experience. Add in the gear? She's done.
Psylocke lacks the strength, and experience of Captain America. She's more finesse than brute force, even in the film.
If you play Warhammer 40K, Psylocke is a Howling Banshee and Captain America is a Striking Scorpion.