The way I see it, that is Garcia's personality, I mean if he could just emulate Oscar when he was young, no trash talking but just wanting to fight the best. But Oscar protege is different, Garcia want's to get all the attention even not related to boxing. But hopefully him and Haney could go fight at 140 pounds in the future.
Everyone has a different personality, that's him, he is showing his real color, he is like Mayweather who loves to get the attention of the people, who knows that's helping him to gain confidence in the fight and probably make more money. We cannot judge though, he is still undefeated til now, so he deserved huge respect as a boxer.