Will Byers will come out as gay in Season 5.
This is why Stranger Things was so stupid to ruin Maya Hawke's interesting Robin character with a lesbian storyline. Everyone loved her with Steve, and then it just hit audience in the face with a stupid plot twist that Robin was gay. If you recall, they came up with this idea after the prior episodes had been written, so Season 3 ended up so disjointed that way, where there was clear romantic tension between Robin and Steve, and then bam, Robin is gay. Last season they tried to introduce a love interest for her. Of course it's a character nobody knew nor cared about, and of course both girls are feminine and pretty, because heaven forbid they show a realistic looking lesbian couple on TV.
They did all of this because the audience was getting impatient with the Will-being-gay story, which the Duffers had always wanted to wait until the very end to reveal, even though they had hinted at it since Season 1. Sometimes you need to just tell your woke audience to stuff it, and tell the story the way you want.
As the link above shows, it's going to be shown that Will is gay, and that he's been in love with Mike, and also resentful about Mike's romance with Eleven. Then he's going to get a boyfriend and live happily ever after. I'm hearing rumors that his being originally pulled into the upside down is going to tie into his internal angst about being gay.
Noah Schnapp, the actor who plays Will, is also gay.