Since we have still disconnect issue I think we should have "Reconnect" option. You see, some time ago there were server issues with that and that issues have been fixed. But DC still happens and still will happen. Even if connection stability issues will be perfect (probably never happen, because new patches might again bring back connection problems) there will still be other "random" disconnect issues.
Today I was playing with friend (1050 + ELO) and we both disconnected at the same time and we both have lost ELO. If you never played at that level you must understand that losing any match here is really painful.
So my statement about that is: unless there will be reconnect option, there will always be connection problems. And really, reconnect option is one of most basic features in online PvP games.
How it should work? The game won't end after player disconnects. If 1 player disconnected then another will play alone until he will finish enemy or that enemy reconnects.
I think that feature is much needed in PL.