We had team ranked back in the day for Feast and it ended for reasons described already on this thread. That being said, if they intend to consolidate the ranked queues together per datacenter, I could see an argument for it coming back. They would need to implement designated queue windows, though, and not allow 24/7 queuing.
Ranked CC should obviously stay solo. Casual CC could do with at least a duo queue.
Frontline is the real victim of this disease. Taking away 8-mans was a gross overkill solution to a problem that involved the 8v8v8 games that happened because there weren't enough of a Grand Company. All they needed to do was implement forced freelancer for everyone (which they did) and abolish anything that isn't 24v24v24 (which they also did).