Actually they have every reason to change contracts because of that, because that is the very thing the lawsuit is about, plus other aspects of their negotiations. WME switched things up so the fault can be put on previous owners and they can prove they changed the policies and contracts once they took over. They already made changes like a 5 year max contract compared to it being frozen indefinitely.
Them not releasing fighter pay is their decision to not make it public, the fighters can make their pay public if they want. Dana has repeated it over and over again there is no gag order on their pay and if they want to tell the world how much they get paid per fight there is no issues in doing so. It's the fighters choice that they aren't releasing their pay publicly.