I get (sort of) why Molag Bal's dark anchors are missing from Vvanderfell and other DLC zones and it's very nice that you thought up a new way to have those same type of casual-group, overland events in Summerset with the geysers.
It'd be nice if you found some story reason to add similar things to the other DLC zones so they are not quite as solo-only as they currently are.