Yes, a series like that wouldn't survive long at all. Whatever it is, in today's market it will have to be at the very top of its game even by TNG standards. But it's really up to CBS what they want to do with the franchise.
Paramount, I imagine they will try to hold onto the current actors as long as they can. But I can't picture most of them sticking around for longer than four movies at the most. Being movie actors, they'll have other things going.