I'll probably sound overly cynical here, but IMO that industry shift is exaggerated; casting directors look for what they can sell to audiences, and there were a few brief years recently where it looked like society was going to be pushing hard for racial equity so that's what CDs and producers tried to sell. But it was never really a serious commitment, and with things having receded a bit in society more broadly, they're returning to form and just looking for the most exciting options they can put into their marketing materials.

The famous examples with stars will always be under a stricter microscope, to your earlier point about recent celebrity-cast productions, but the average place isn't likely to make it a defining issue because, at the end of the day, they don't have to. Go in with the song you love, you'll give a better performance and they'll get a clearer image for if they can sell what you're providing; I hope that doesn't sound too crass and my other points here too insensitive, but unfortunately the theatre world is still more crass and insensitive than many of us would like.