I don't know if this has been suggested but playable Drow?
It has been discussed before, and the Drow (not playable, though) are even included in the 6.2 version of Masterwork.
Unfortunately, the Reborn version of Masterwork is under process of heavy, let's call it - "vanillisation". And by that I mean adjusting every game aspect to fit in the Dwarf Fortress lore. The Drow are part of DnD, not DF, and thus do not fit in the lore at all.
But succubus and gnomes and orcs are not part of DF lore either! and Hivewasps are completely different! so why would drow specifically need the cut when this game will probably never fit DF lore to begin with.
Because they're extraneous evil cave elves for all intents and purposes when there's developed and playable races to take thier place (orcs spring to mind.) They offer nothing that your civ can't get on its own in some fashion.
While the other races don't fit whatever the hell is considered "lore" for something like Dwarf Fortress, they're fleshed out and playable as well as optional, and cover all the bases. Drow meanwhile are just an additional trade partner/enemy with zero playability and explicitly drawn from a separate IP (while the rest were either independent, though drawing on stereotypes, or in the case of kobolds and even the dorfs themselves, simply adapted from existing content in the game already.)
I'm all for keeping them on as a Fort Defense- type Race, just to add decently equipped not-bigger-than-a-dwarf things to potentially fight, but otherwise they simply don't fit with the other races, and in my opinion, never really "fit' the mod in general.