Even if this is brought up at the next premier league meeting, I think the only way this gains any momentum is probably a legal challenge from forest or everton.
We know about the allowances now, we know the amount, but we don't know the exact reasons and justification. It'd be far too easy for them to shrug their shoulders and claim they did it all fairly and case by case, without divulging much else.
What should be of major concern to almost every club is that fact there has clearly been a dialogue here with united, which has payed dividends, probably quite literally. So that process of communicating, what was it and were others given the same opportunities to build up that relationship and understanding? It's clearly a different level of communication than is afforded to the rest of us.
That's even before we get to the extremely questionable allowances themselves. I'd love to know exactly how these were justified, but as said above, without a legal challenge I'm not sure we'd ever know. So the best hope is to raise awareness, hope the rest of the league's turkeys stop voting for Christmas.