The joke is that until then, Konsi was still considered a Junior priestess on a bureaucratic level, and the high priestess is just like "I can't believe we haven't changed her position, terrible thing to overlook in the paperwork"
The origin for the draconic gods is a bit different. Once, they were a whole, one.
In the dawn war, a primordial lord cleaved the arch-dragon deity in two. Those halves would transform into Bahamut & Tiamat, who would then team up one singular time, to bring down the elemental. And then they decided not to ever ever agree ever again.
That's the short story of their origin.