Vampire the Masquerade
Mat has no idea who this guy is. He is of lower generation than you. While Mat has been secluded away, he was still tuned in to meetings and the friendlyness than clan Gangrel and the Bruha have.
While he is “slightly out of touch” and an “outsider” within clan Gangrel.
Still, if Mat hasnt heard of this guy, most likely the other clans hasnt heard of him either.