This is not the case. I currently have players on my negotiation list with 96%, 97% & 98%. Out of the 20 or so players i just clicked on only one is at 99%.
I can even make offers on much lower level players too. I'm level 48 and when someone offers to buy a player from a lower level friend of mine that player appears on my list with the 24hr countdown timer. I currently have 2 players like this, one is 78% and the other 57% and I can make an offer on either if i wanted.
The problem is my association friends, or anybody at the right level, should be able to make offers on my players but they can't.