Will it come with a ranked ladder? Since most matchmaking systems already use a hidden rating, you could just make a queue you can join where it's, you know, not hidden.
Pros:
-Hardcore community would have a place to go train in all seriousness.
-Less stacks and stomping of the unexperienced.
-Less stacks against smaller yet big clans.
-This is a big one that would really help out: More player retention due to a feeling of progression that the game otherwise lacks. (And it's perfect that way, but you know, niche.)
Cons:
-Would need more mods and more of them to be readily available.
-All sorts of new moral dilemmas.
-Community might become a little worse. (Kinda like novice games already are, but extended.)