1. this isn't a repost
2. it works
3. this is no exploit to gain teamrating, this is only for the streak achievements!
You also can push your teamrating with that, similar exploits in the past based also on playing versus lowteams. The problem at that time was, that if you played against a low team which is skilled but just started a new team, you lost up to 32 rating. Now you always play versus really bad players, so its pretty much save.