Concerning the whole "Jensen said Destiel doesn't exist" thing: I always thought that he has to say that. I mean, we know how some of the more powerful people on the show think about it, and I could imagine that he had to sign something so he wouldn't say "something wrong". I mean, it's still him who decides how he acts out the scenes and if he really believed it does not exist, he could and I think would have acted out many scenes differently.

I…don’t think it’s that complicated. They have NDAs but they drop spoilers all the time. (Looking at you, Mr. “It’s a real eye opener”). They also get very clear talking points at the top of a season and outlines and stick to those, trying not to deviate to much. 

I think Destiel is something the writers don’t ever want to count out, but I also don’t think there’s a vast conspiracy about it or keeping it quiet. 

What I come back to time and again is that when Jensen says “Destiel doesn’t exist” he’s not talking about the subtext that we ALL see. He’s talking about Cas and Dean secretly banging all these years. And he’s right. There’s no secret story about them that we’re not being told. He just doesn’t get that that’s not what we’re talking about.