I haven't done the Studium quests, but before you can claim that statement as proof of an eventual natural rejoining, it's important to define the "original state" that the currents are supposedly returning to. Are they talking about the pre-sundered state or simply the state immediately before both the pseudo-gods who have been stabilising the currents for millennia dissipated into the aether?

Also, if the aether currents are unique to each shard, then their state wouldn't directly have anything to do with them rejoining or remaining apart.

Narratively I think a natural rejoining would be very unlikely after they've staked so much on the value of the individual souls of each shard and that it would be a tragedy to lose them.