It's not about having "quotas" as you put it.
It's about continuing the Mortal Kombat tradition of having diversity in the cast.
An all white male Justice League with token Wonder Woman is boring in a comic book, because there are not enough unique perspectives.
It's like if all the characters in the game except one were male and people said those complaining wanted a female "quota" when in reality,
ladies kick ass too.
So Reyes as Blue Beetle, Montoya as Question, Choi as Atom, Vixen, and of course Static would be great characters that should be considered.