I'm probably wading into shark infested waters here, but here goes anyway.
In my opinion, diversity and/or color-blind/color-conscious casting is not a one-size-fits-all argument. There are some cases, like Hairspray or Miss Saigon, where specific racial casting is literally part of the story and it would be inappropriate and miss the point of the story. A Latino Seaweed or a black Kim wouldn't work because the stories are specifically written to be about characters of specific backgrounds.
Then there are shows where they were originally cast as white characters but it doesn't matter to the story. She Loves Me, for instance, could support any races in any of the roles. Some of these shows don't necessarily specify race, but casting non-white actors in the roles may create additional context that may or may not change the thematic focus.
And then there's shows like Hamilton, where the casting is deliberately against the "expectations" in order to make a thematic point that is crucial to the show and its aesthetic and themes. It's literally about reflecting modern American diversity and immigrant heritage in the personas of the Founding Fathers. They're race-specific for thematic reasons.
West Side Story, I think, falls into the first category. It's supposed to tell the story of Puerto Rican immigrants and white Americans (vaguely hinted to be of Polish heritage, if I remember correctly?) clashing. Even in a concert version, a white Maria (and, for that matter, a non-white Tony) would seem a little off. I can't imagine they couldn't find a single Latina who could sing the role.
My point being that each show is its own individual thing and something that works for one show might be inappropriate for another. just my two cents.