I don’t think he’s officially out until this year’s Pride book. I picked Maggie, because she was one of the first. They implied it for a long time, and it even made it into Superman: The Animated Series.
Ths fact you put Helena Wayne in here is fascinating but also personally awesome.
I don’t think she is canonically lgbtqia yet but I do understand in Batman/Catwoman she is a lesbain and I do like to believe in Earth 2 she is Queer.
Jon Kent would be my second choice, but his story is too new. Tim takes the cake for being around (and relatively high profile) for the last three decades. He’s also an awesome character. Especially after Tynion wrote his amazing run.