I don't think there has been any official lore released to support it, but I see no reason that this character background couldn't work. Unless the area is fervently anti-miqo'te, I'd think you could make a go of it. From what I've seen, it isn't. Non-humans definitely weren't well thought of during the War of the Lions, but we also didn't see any that weren't monsters. In 12, Dalmasca seems to be an extremely diverse and accepting area. In FFXIV we've seen Hyur, Bangaa, Seeqs, Viera and Moogles. It would seem strange for Miqo'te to be ostracized.
So I say go for it.