Can we have a connection quality check for everyone at the launch of every matchmaking?

It's annoying to start a game, then one of the players has connection problems whether it be high latency, packet loss or connection drops. The problem is by the time somebody realize he's having an unstable connection, the game has already started and it's too late to cancel. So one team begins with a huge disadvantage and loses.

The client would check the connection quality every time someone launches matchmaking and receive a warning with the connection statistics. And forbid playing for people with a ping above 300ms or so.