Also worth pointing out: It's been rather established in-universe fact that magical treasure maps that open gateways to ancient treasure vaults are a reasonably known thing in the world of FFXIV. Hell, a bunch of them lead directly into Radz-at-Han's canals, of which we can just walk up to the gate of, and multiple quests directly acknowledge.

I remember when that was the first hook announced for 6.1 I was pleased at how not only was it refreshingly normal, but it folded in a part of the game that actually makes complete sense for where everyone are as characters after Endwalker. Straight-up, the opening hook for 6.1 was 'the WoL and Estinien start a map team on a lazy day when they had nothing better to do', and that tracked completely.