Someone on Reddit got this WoB a few hours ago....
Sorry, what? How? Did the regional magics exist prior to the Shards being in the Cognitive???? Because AonDor is pretty specifically based on Arelon.
(Could mean a normal, non-magic city, but "when was Elantris built" feels like it's pretty clearly not saying "when were three buildings built that would become a city down the line", it's about the magical power enhancer that makes Elantris Elantris.)