Originally Posted by
Erik Setzer
To be fair, none of them really "survived." They're new peoples... though apparently based on the old races. I still haven't seen an explanation on how that works, though there's an easy explanation they could have run with if they wanted. (The Slann create whole species, why wouldn't they be able to try to recreate the species from the world-that-was while protecting parts of said world as the "Realms?")
They can add all kinds of new Dwarfs with no connection to the old ones, because it's basically a new species (still Dwarfs, but technically new).