Caismero always talks like that. I don't know if he's either getting to the opponents head or he's just hyping the match up to sell it to the fans. Or he did it for both reasons.
I've read somewhere,
(maybe here or some articles?) that according to Casimero's camp, his trashtalk is a way to promote the fight because Casimero itself doesn't know if he can generate good revenues from PPV or ticket sales. Maybe the majority of his fight wasn't able to yield good revenue. To confirm it
(which I doubt sales aren't good) I will try to search for it or if anyone has statistics for it, I will be glad if it will be shared here.
No problem for trashtalks as long as he can prove it on the ring. It's just that it's unusual to see a PH boxer doing some trashtalk.