What if she was?
You have to ask the Australian Open if they named the court in honor of Court's tennis achievements or because of her personal beliefs?
I think we all know the answer.
Her name will stay.
of course maggie got her name stamped in the arena because of her tennis achievements but that doesn't mean that if her vocal personal beliefs (whatever they were) had been controversially enough at the time, the tennis federation of oz would have still decided to name the arena after her.
at the grand scheme of things tennis is only a sport and there will always be more important things for the people of a any nation. i can assure you that if maggie had showed critical opinions about sensible topics like being pro-terrorism, anti-australia or whatever, she would have been forgotten and most likely she would have even been banned from playing in tennis.
so, in response to your "what if she was" a neonazi, i think it's pretty fair to say that it does matter a hell of a lot.