This is why you are asking a stupid question:

1) 99% of the time, people in game are HAPPY to be in game. Why? Because THEY CAN ACTUALLY GET IN GAME. Lately it's been taking TOO DAMN LONG to find and GET into a single game; do you HONESTLY THINK that people will want to WILLINGLY DISCONNECT after successfully getting into a game? You are seriously single-minded. I can think many other possibilities that a person would "willingly disconnect", whether something important came up or maybe a friend came online and wants to play with him.

2) Even IF the 1% disconnect on purpose because of whatever reasons they have, DO YOU HONESTLY THINK THAT WE WILL KNOW WHETHER HE WILL RECONNECT?

3) Assuming the person is in a party or a friend. Okay, it's a given we will have knowledge of whether he will want to reconnect, and 99% of the time, the person WILL WANT TO RECONNECT BECAUSE WHO THE f*** WANTS TO LEAVE A GAME THAT IS HARD TO GET TO BEGIN WITH. So YES, we KNOW the person will WANT to reconnect to the game, but whether he CAN RECONNECT or NOT is a COMPLETELY DIFFERENT ISSUE OUT OF OUR HANDS. It is dependent on whether Steam will troll him or not. Yes we know that he will want reconnect but can he? Thus begs the question "will he reconnect?". Whether he can or can't only a friend with him will know that. If he can then we wait, if he can't then we simply proceed with the game. Rather to be in a stalemate until one guy goes "f*ck this" and just resume with the game because no one asked.