Because canezerra wants people to be respectful to her and make sure his fans don't send her hate?? Idk about you but seems like a good bf move even if he was shitty during their relationship.
Because people are always going to be nosy and interested about things that don't concern them and the information will always come out eventually even if it's not from canezerra himself, better just get it out of the way before rumors and hate builds up on either side.