My high school class was in mid-'00s, and there was one girl who very much had that butch/tomboy vibe going on. I drifted away from the class, so only heard rumours after graduation, but I think she never actually came out as anything. On the other hand three others of us (two of whom, including myself, I never would have guessed back in high school) eventually came out as various shades of queer :D

There were a couple of people who were "different" that, in hindsight, it was very obvious they were "confused". Some of them came out later but were much less obvious.

I was in high school in the late 70s and early 80s. Nobody was out. But people kind of knew. One time I was on a train into the city (San Francisco), and I saw two students along with one of our teachers headed there. I thought that was kind of cool, but seemed also a bit dangerous and ill-advised at the time. I am fairly certain that our very popular senior class president was gay. Very sadly, he took his own life.