As I said, I don't know their full guidelines, so I see my observations in this as in no way definitive.
On the surface, I would agree with you. This is what I am trying to figure out, though- the rules recently changed to where potential violations are no longer being made public until the process has played out. In this particular case, the card was being moved to another city and the UFC had to explain why, so even though the process hadn't played out, and Jon hadn't been convicted of new use, they had to release at least some of the information. This could be the reason that only one was released, as the rest were not acted upon because they weren't seen as violations.
I wish they would have been completely transparent regarding the other tests, and the timing of the policy change that made them not release results until the process has played out is at LEAST very convenient for Jon. I can't argue those, but I think the idea that this is a cover up with USADA in cahoots isn't fair given the current evidence.
Dana's a scumbag and the UFC didn't seem to act in good faith, but I don't think any of us know enough about USADA's side of things to assume that they were complicit in a cover up.