I think what you just stated was the, "Battle Sever," solution. Which was covered a couple patches ago. The problem is, what if the other player does no reconnect? That's when ELO, Trust, or whatever comes into play.
The battle server does not allow re-connections at all. If one player drops out, it's over.
The point of a re-connection system would be to give the disconnecting player the option and time to reconnect, if he doesn't want to, he concedes.
Dota2 and Cs:Go do this pretty well but in their case, the true game state actually runs on the server and I guess that makes things much easier. Mimicking that on a p2p system probably creates a load of other issues.