Well you know, Tannehill has always struggled pre snap and knowing where to go with the football. He doesn't see the entire field. He's always had a tendancy to lock on to his first read and struggles coming off of it. He's at his best with half field reads. A lot of times you can help quarterbacks who don't see the entire field well by using 3x1 alignments as opposed to 2x2 - but even that didn't help him.
I don't know what these coaches are teaching the TE's, but Gesicki's technique isn't the way I would teach it. He's never able to come to balance trying to block like an offensive lineman. He needs to be coached to block as if he were a running back. He needs to split his guy's crotch with his outside foot and force him to go around him. You always want to attack the inside leg of an outside rusher - meaning you have your "full" body in line with his inside leg as opposed to only half of your body. The rusher can go either way he chooses if you don't, and you'll lose unless you win the hand battle. That's just poor technique being coached.