No, I don't think the athletes keep track with the bulk of the testing changes. Their management/trainers/gym might, but I doubt most fighters have the time, desire, knowledge, etc. to keep track of things themselves.
As for "inside knowledge", no I doubt any UFC fighters have any sort of significant inside knowledge.
Another thing you're missing, changes to tests (and therefore their accuracy), which tests are done on which samples, etc. isn't relayed to the athletes. Changes to the banned/prohibited lists are disseminated to all the fighters, but the details and specifics of every new test isn't.
In Jones case, Dimspace said that the test for turinabol used to only accurately detest usage if done within days of dosing. The new test however can catch usage weeks-months after usage. That change alone could be why Jones popped, but more likely he was always using and just never had his sample tested specifically for turinabol until now.
Lance Armstrong admits he used PEDs for close to a decade before he was definitively caught. There's been tons of Olympic athletes that weren't caught until years later.
And keep in mind:
"Jeff Novitzky, the UFC’s vice president of athlete health and performance, said newly developed drug tests could be performed on samples that have been preserved in connection with the promotion’s out-of-competition drug testing program.
So blood and urine that’s been kept frozen in World Anti-Doping Agency (WADA)-accredited laboratories could be re-tested for new PEDs, which opens the possibility of UFC fighters failing drug tests years after a particular bout."
SOURCE: http://mmajunkie.com/2015/08/jeff-novitzky-ufcs-usada-samples-could-be-retested-years-later
So chances are highly likely that Jones will pop on another test in the near future as USADA goes and retests his old samples.