Reverse proxies work because they're not behind restrictive NATs, and having a few central servers that are not behind Symmetric NAT is a surefire way to establish an ISP-granted monopoly. Even if that somehow worked, this completely breaks P2P for consumers (which I think you intend) as well as torrenting without, again, a central NAT-punching TURN-like server. So yeah, address exhaustion is done but so is the Internet as we know it.