I'd rather MCU develop POC from the X-Roster than take known white characters and make them POC (to me that's just a lazy way to claim diversity).
The X-Universe has a lot of characters that have gotten little to no real love in the movies
African America: Bishop, Shard, Sync, M, Penny, Emplate, Storm (freaking deserves better than the X-Movies, ) Darwin (freaking got done dirty in First Class)
Native America : Forge, Warpath, Mirage, Silver Fox (yeah she's mostly there for Wolverine's Manpain)
Aboriginal: Gateway (I always loved him popping up and sending people on adventures)
Latino: Sunspot, Dr Reyes, Skin (poor, Angelo), Angel/Tempest, Empath, Rictor, Goldballs (his name sucked but he was sweet).
Asian: Jubilee (my fave, deserves way better than the movies gave her), Tyger Tiger, Sunfire, Silver Samurai, Shanobi Shaw, Yukio (deserves better than that shit in Deadpool2 - was good in The Wolverine), Amiko, Karma, Mariko (see Silver Fox - but I really like Mariko), Viper
There are probably a ton more, these are just the ones I remember from my reading.
Put them on the big screen, make Storm the leader she always was in the comics, show why Jubliee is the last X-Men (yeah, probably retconned) and, skip that Vampire shit, I want my Firecracker back