There's no worries of being split necessarily, but there is theoretically a way to be stuck in between the lifestream in a normal situation with aetherytes. Although, that's a fairly rare situation. That usually has to do with the situation of if the aetheryte the person is teleporting to happens to be destroyed before they arrive.

I can assure you that I have never heard of such a thing actually happening though. There is the possibility, but destroying aetherytes are fairly uncommon on its own. There has only been a few instances that.

Whether or not something like that will occur with these are still unknown, but I don't think the chances are likely.