The reality could be much more straightforward.
Adam and Kara were doing the same things as other NOP runners, regardless of the fact, whether it is PED, yet undetectable drugs, or still legal methods (like using autologous blood transfusions was completely legal up to mid 80's - something along those lines).
There is no gag order, or contract. That would be a legal nonsense. It might be a simple auto-protection silence. Who wants to tarnish his/her best performances late in their career, or after retirement, especially if they could ride on the past performances long into their retirement?
Why Gouchers left then? They weren't getting the best stuff, like the new shining stars...
For the inspiration- read Hamilton's book (Secret race), and you will understand that not verybody in the leite team is allowed to be on the best stuff. Then it creates tension and resentment.
If there wasn't for double bust of Hamilton, he would never reveal the details of doping and receiving the much wanted white paper bags for the super elites. Why would running be any different from cycling?
Please stop being naive...