I wonder why people find it so important to note a person had/have homosexual sex but not mention they had/have heterosexual sex.
There's evidence to suggest he was [also] interested in women. Wikipedia doesn't mention it but a BBC article, http://www.bbc.co.uk/news/magazine-22099082, says he was engaged. Of course that could have been a way to court interest from [female] fans; but it seems equally others could have lied about the extent of his homosexuality. Often people mistake flamboyant-camp for homosexual, it's possible to have either without the other.
The whole Wikipedia page for Liberace appears to be an attempt to force him in to a mold that he refused repeatedly. Perhaps he was asexual as some reports hint, or maybe bi-.
Not to mention before that, there were people, even in the small town south, that everyone knew was gay but just didn't discuss in open terms.
Now it's true the cultural stereotype for "gay" was the Village People or Liberace or whatever, but a large number of people knew ordinary gay people as well.
Of course, even today, and even in a place as open as San Francisco, I suspect most everyone knows more gay people than they think they do. I know that's true, in fact. A lot of people just never talk about it.