That's ridiculous.
Essentially you're suggesting that If you're in a 1200-1300 tournament and you are improving too quickly then you can't win.
I'm in a 1300-1400 tournament right now and my rating is just over 1500. I am still playing the last of the two games in the first round though - because that game just took that long.
Kicking people out of a tournament (because everyone goes into a tournament to win it, not just to play) just because they improved along the way is punishing people for succeeding.
Not to mention how offensive it is to call it "cheating" - how have I cheated?