He's been Noxian just for the General, otherwise he hates Noxus.
I don't think that Talon ever really hated Noxus. In his old lore, he bought into the whole social Darwinism thing just as much as everyone else in Noxus (his great contempt for the weak, his only respecting Du Couteau and no one else because he was the only one who managed to best him in combat, his killing Kavyn as a child because he considered him a liability). The guy was just cynical and antisocial because of his upbringing as a street urchin struggling for his next meals, rather than because he was didn't like living in Noxus specifically.
I'd say he belongs in Noxus, since his attitude fits pretty well there. He's ruthless, highly skilled, cold and dangerous. Though as for updating the lore, I'm not sure exactly what else they could do with him if they get rid of the Du Couteau story, since Talon's entire thing before Du Couteau in the old lore was "works for himself, basically kills anyone who tries to force him into their fold." I imagine that if they got rid of that, they'd make him something of a wild card hired blade, extremely sought after for his skills, but perhaps selective about what jobs he takes. Something of a legend in Noxus, this assassin that leaps, tumbles, and climbs from buildings and walls to kill people. Maybe they could even set up something of a rivalry with him and Katarina over whose skills at dealing death with the blade are superior, that is, if they're no longer allies and/or adopted siblings in new lore.