In a vacuum, that doesn't mean anything.
Most specs have a good core rotation - well at least most of the specs I'm interested in playing. Adding a new button to press every 30 seconds to 3 minutes doesn't really add much depth. Maybe some fun new toy abilities for flavor would be nice. I don't need new abilities thrown at me every expansion just for the sake of it.
That said, that doesn't mean there isn't room for new abilities or reworks or rotations.