For what it's worth, having Shardra replace the Oracle iconic would also increase representation somewhat, while dropping Quinn would likely not help with that. Not necessarily top priority, but Paizo seems committed to have as much representation in their official products as they can and given the general concept of the new oracle, it wouldn't be a huge retcon to have Shardra as the iconic Oracle.
Another big potential that I'm sure they will explore in time is sorcerer feats specific of a given bloodline. The playtest gave us a hint of feats specific for spell lists, but nothing stops Paizo (or a 3PP or you, at your home game) to creat feats that bring out the flavor of a specific bloodline!
I think this is a small part of what they have been saying all along: the 2e system is built to be more expandable (and, therefore, customizable) than 1e allowed them to be. Hype!
I'm normally a lurker, but I have multiple players at my table (we come from 5e, so it's expected) that would love to have the casters all behaving like the Arcanist. As for the sorcerer, if they boost the bloodlines with extra slots or something else to make the sorcerer viable, it may work. I don't see how the game balance would suffer from the change, but I'm no designer... It's a sacred cow that should have been slaughtered long ago!