Not the First, we know the creatures there aren't related to the First Brood. I want to say it was reddit, but I don't remember. I agree that Azdaja will show up wherever the plot goes next and could use them, but that I hadn't considered one of the other Shards now feels like an oversight.

I could well-imagine the raid questline for 7.0 involving dealing with one of the AWOL Sundered Ascians who was prepping a Shard for a Calamity and is now twiddling their thumbs and causing mischief because the endgame of their bosses is no more, and during this raid we gain as our main ally Azdaja, who chased this Ascian into the Rift and into the Shard, accidentally stranding themselves and therefore placing themselves as the Shard's protector as a miniature copy of Midgarsormr.