I want all the lore masters to come up with a plausible lore friendly way to bring back an extinct race to Tamriel. Dwemer, Lilmothiit, Left Handed Elves, Ayleid, Chimer, Aldmer, Nedes, Kothringi, Keptu are all options. GO!
They left it open for the Kothringi to return. Dwemer, I doubt. I don't know enough back story to make a guess, but judging by how Rebel reacts to that possibility, find it unlikely. Aylieds, if I recall, may not actually extinct, and are awesome at hiding. Left Handed Elves are believed to have been destroyed with Yokuda, so I doubt they are around. As I recall, Almalexia managed to turn her skin gold again, turning her back into a chimer. Again, not sure. Aldmer and Nedes are both ancestral races. They aren't extinct until the descendant races are all extinct as well. As for Keptu, I can't say I've heard of them. The UESP says they are a race of man, but there isn't an actual article. Any info would be welcome.
They say that a dead man tells no tales. I disagree. They tell tales all the time, we just have to learn to listen.
Beth guys aren't that stupid otherwise they wouldn't have dumbed the absolute **** out of their game to appeal to a wide market and make ****loads of money. They're greedy and don't care about their older fans but not dumb.