In the game we meet Barcus Wroot, who is a Deep Gnome that's been living in Baldur's Gate for years. And if you ask him what he's doing outside of the Underdark, he says;

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Ignorance is alive and well it seems. Deep Gnomes are not restricted to the Underdark you know.

So going by that, neither are the Drows. Minthara for example is on the surface, as are other Drows. Although they are very rare to encounter outside of it, they are not restricted to it. So at best we might get some interesting reactions, but I don't think it would be weird.