Yeah but this is not on Larian. Wizards of the Coast was the one who kinda walked back on the distinction btw sun and moon elves in 5th edition. Larian just follows the lead.
Only mechanically, even the PHB mentions Sun and Moon elves under high elves, and the SCAG mentions Star Elves. This isn't a problem in PNP where the dm can use the proper term, but it a problem in BG3.
Perhaps the TCoE will have a solution for this, after all I suspect it's where the idea for Lolth-Sworn Drow vs Seldarine Drow Arised.