I never thought about it, but that's a good bargaining point. $125M would currently cover 6 teams and $150M would cover 11 teams. If they kept it to $125 floor, you'd have almost no teams voting against it.
On the high side, you have 5 $300M teams, with two being fringy. If you added another 125% penalty for > $315M, you likely only lose 3 votes. The league probably passes it, and the players might not care enough to suffer the poor optics.