They will not be.
Dark elves are an old concept, but the dark-skinned "drow" are a Gygax invention. We have a few elven subraces, some of which will seem more familiar than others. In addition to the subraces, there is significant cultural division between separate groups even within one subrace. The elves that came across the sea with their human allies to settle in the Dyrwood encountered Glanfathan elves that looked almost identical to them, physically, but spoke a completely dissimilar language, dressed differently, had different values and customs, and lived virtually at a Stone Age level of technology -- all this despite abundant evidence that an ancient empire once stood around them. As a result, the elves who settled in the Dyrwood tend to feel much more kinship toward human neighbors, with whom they share a language and hundreds of years of coexistence, than the Glanfathans.
Thanks for the info.