Most likely they won't include dragonborn so why do you think they would add kobolds?
Actually they said all base Races will be in, Dragonborn are a Base game race.
Yeah it would be strange to arbitrarily exclude a PHB race when they've included drow (which are noted as being EXTREMELY rare!) and Githyanki (who're relevant to the story, but also almost unheard of in their rarity)
Granted I think the idea of excluding any kind of player race option on the grounds of rarity is, frankly, a load of B.S.
Player characters are the *exception* in the setting, not the rule, so them being exceptional in terms of race is not only fine, but I think a good goal for options. Given that they're a dime a dozen, it's a granted that there's going to be human adventurers everywhere, but Dragonborn? Kobolds? Goblins? That's when it gets interesting to me. Not many stories about them, whereas I have a backlog of probably 30+ forgotten realms novels about demihumans.
