The advice is probably valuable, but YC (and countless others) make the advice pretty available already if you're willing to analyze what's already written and recorded and synthesize their advice with your own facts. I say that to mean it's out there, but not with any kind of hand-holding, but I would also wonder how a decentralized/franchised type of YC would really accomplish that.

Beyond that, these sorts of things exist in many cities, they're just not called YC. I'm not against it or anything, I just think that what you're proposing exists in some form already, just without the brand. If YC could add to that experience on a larger scale, it's a great idea. Not trying to talk you out of it or anything.