I wouldn't call it trash talking - trash talking is more of a goofy American term - I'd call it slagging more than anything.
Folk mention that without the 'trash talking' and not being able to get inside his opponents head, he's screwed - I think Cruz said that. But he forgets that before getting in to the UFC and fighting in Cage Warriors and other promotions earlier in his career, you meet your opponent more or less at the weigh in.
At the end of it all, it all boils down to what happens inside the cage. Plus, I think that Conor putting away some of the fighters in the round he predicted rustled the McHaterz jimmies. It was all pre-planned, the ref was in on it for the Mendes fight stopping it early, Poirier dropped after getting hit in the back of the head, Siver went down from a phantom punch.