I figured the "Dancer" joke was once again the devs poking fun at the lengths people went to trying to figure out whether or not it would be a job added to 4.0.

Just the same as the item description states that the wind-up Lyse is "[m]ost certainly not a repurposed wind-up Yda" can be taken one of two ways: the Yda / Lyse switch was always intended, or the devs are admitting they didn't know what to do with Yda so they retconned her into Lyse for Stormblood.