I think sometimes parents get too heavy-handed with liberalism because they want to make extra-super certain that their kids know it’s okay to be gay. And that’s a good thing, really. They’re making space for you to be any kind of person because they love you enough to accept you however you are. And that also means they’d be fine if you were straight.
My parents did a similar thing. Every time a gay character came up on TV or whatever, they’d say, “Just so you know, if you turn out to be gay, that’s totally cool with us.” So I knew I could feel comfortable and confident coming out to them when I was 15.