Adults projecting sexual orientation on minor [age] characters is a little weird (not specifically directed at you).
He's not anything until he (Will, or the show runners' claim) he is.
Being emotionally fragile, especially after trauma, especially for a teen, is not an automatic indicator of homosexuality.
He perks up at any reassurance and comfort he receives, not just Mike's approval, it's not just puppy eyes.
There's still ambiguity about his pain being over the eventual loss of his friends, not just Will, and they're the only ones that can ever know what he went through.
He's still cursed, much like Frodo, and every waking second is fear and doubt. See 3 and 5.
I know people want representation. I know that having one lesbian on a TV show is the most a lot of people in the community get. I know also that any time that a male character looks at any other non-family male character with as much as a slight misty-eye, people get in a mood (and it's not always a polite and accepting mood).
I understand the fine line between stereotyping and creating characters with real world parallels. As much as I don't want to "just good pals" Will re: Mike, I just think it's better to let the story play out, instead of having a bunch of people queerbaiting themselves...
I remember how half the fandom just assumed Max was gay because she was an 80's tomboy while were working their way through the episodes. Or how Billy was totally gay because he was a George Michael Denim Daddy, but he was also a womanizer so he was totally bi. Maybe he was, but he's dead so that belongs to the fandom, not the fiction. Will is both a minor child, and still alive; his journey still belongs to the fiction.
I want people to have their sympathetic and proxy characters. But I also want everyone to just be okay with a straight male being a bit soft and expressing himself without it being immediately a queercode.