I don't come down on either side of this argument, as have no clue whether or not he'll leave; but I find you put a serious amount of stock in words that managers, chairmen, and footballers say. Poch also said he'd leave if Cortese left - and he hasn't; and it's in my view pretty naive to expect people in the football world to stick to what they say. Things change - experience tells us this. Look at Cortese...
When I talk I tend not to speak in riddles or try to manipulate people and I expect the same from others. So it's no surprise that when someone says something seriously, I tend to take their words as the truth until I have reason to doubt them. But then again, I'm no fool either. However, there comes a point where being cynical of every piece of dialogue one hears or reads becomes so degrading to one's own opinion forming that it's a good idea to clean the slate and become open minded. Anyone can point to any situation in the past and say... see, I was right about that, after all.
I think Cortese is possibly the worse case scenario you could have picked. He didn't want to leave, but he wanted to run the club his way, with no interference or compromise. It had worked astonishingly well. That has nothing to do him with walking away. Poch saying he'd leave if Cortese left can always explained by the fact that, by his own admission, Cortese's last words to him as a Chairman was, please stay here, and that Katherina had said nothing changes, we still have the same ambition and we back you.
Now you can double-think that all you want, but isn't it simpler just to accept it for what it is, until events prove it incorrect..? Personally, I haven't the time or the interest to double-think these people because 1] I'd be guessing, and 2] me thinking I knew better wouldn't change things one iota. I don't indulge in face saving exercises. If I'm wrong I front up and say so.