The fact that they were publicly exchanging barbs about negotiations possibly means nothing, and if anything it supports my theory..
One of the reasons for hiding the failed PED test I am alleging is to keep your options open. If no one knows Jon failed a test and/or is (provisionally) suspended, then the UFC could bribe USADA or an arbitrator to cut his suspension short. That would allow them to make Jones-Ngannou if Jon agreed.
In fact, the public complaints on Jon's behalf signal to me that I'm right. Why? Dana would use this against Jon in negotiations. Dana would control Jon's future with a failed PED test. One word from Dana, and the information becomes public and Jon is facing a lifetime ban for his 3rd strike. This would allow Dana to lowball Jon, and Jon would have no bargaining power (other than to never fight again, anywhere).
I think this is exactly what happened. Jon wanted to get paid, and Dana wanted him to fight for $500k + PPV points. Jon wanted more guaranteed money, and Dana probably said "fight for your contract money, or be banned for life".