Drow were already a subrace. We’re not getting more varied drow, we’re getting two other, different subraces that we’re being informed count as drow too because it’s in their name.
If drow are so culturally varied as you suggest here, why did they need to be changed in the first place? What is this change meant to actually fix?
If you believe subraces are cultures, it was already cultural. Drow are a subrace of elves.
Oh, don’t get me wrong, I don’t think these new subraces are a bad addition to the lore. I just don’t think they actually address the problems with the drow. Because the only thing this changes about them is adding Unu in front of their name.