Same as for all the other TES games, there will be no 'canon' race or story for the Dragonborn.
People are too obsessed with canonicity these days, while a prime tenet of TES is ambiguity.

they're true sons and daughters of skyrim

in my opinion there is no right or wrong dragonborn, doesnt the lore say that the dragonborn can be anyone of any race, any skill set and motives? this topic is pretty pointless lmao