I believe I generally understand the concept of the (trans, not Star Trek) usage of "The Prime Directive" but as a cis person, I don't really seem to get why. If a person you know and are close to starts to act or talk in a way like they are possibly trans, why is it... not proper, for lack of a better term, to genuinely tell them "I think you might want to seriously explore these feelings"? It feels like you should? Like you should be reassuring to someone who feels like this?
I'm not there, but I think I would want to minimize the kernel of doubt that I'm only expressing my gender because someone put it in my head. I think it's something people would figure out, but I think it could save a lot of grief and responsibility for everybody.