Mwangi introduced more dragon types that those with the wyrmblessed bloodline can choose, such as imperial and primal dragons. Can a barbarian with the dragon instinct choose these options for their instinct as well?
Also the kobold ancestry mentions "Kobolds most commonly share the coloration and some physical resemblance to chromatic and metallic dragons, but others closely match different sets of true dragons—notably esoteric, imperial, planar, and primal dragons."
Does this mean kobolds can choose one as their draconic exemplar or are they still limited to chromatic or metallic dragons?
RAW currently suggests no to barbarians (only draconic and wyrmblessed sorcerers were specified in The Mwangi Expanse), but I don't see a reason why they wouldn't be in-game. The kobolds description on the other hand set a clear intention. It really feels like it should be available to all dragon-based things to me, but it'll come down to your DM if their cool with it.