Yep, I don’t know about Roo’s but with rams changing the flock dynamic can totally change their attitude. Our biggest ram, I’ve never had any problems with, even though I was told he tends to charge and butt people. Well, turns out when he’s with the ladies he’s fine, but take the girls away and he becomes a total jerk (yes, he finally took a run at me... after two years of being sweet as pie). So, maybe removing the Wyandotte would be good for everyone, and he’s not human aggressive which is a big plus for the new owner, and he can learn to grow up, be a man, and treat his ladies right!^^^
Find out what she wants a rooster for. If it's for a pet then the wyandotte. But for a flock rooster, I dunno. If he were the only rooster he might feel more like he had a job to do.