Even if Mike was gay he still wouldn’t be into Will
Exactly. With El we see that while Mike does take on a doting role, El can do the same back. Both of them have similar drive, passion, and honestly personality. If we take that as an understanding of Mike's "type". Will doesn't fit it. Not only is Will not able to put back the same amount of care Mike gives he also does not match him in drive, passion and personality.
If we do not take El as his type but just try to see it from Mike. Imo Mike needs someone that is like him, not someone different from him to "balance him" but someone who will actively support him. Will doesn't do that. Do not come to me talking about s4 bx half the time Will was talking about HIMSELF and pretending it was to comfort Mike and also Will does not support Mike being himself at all that season. People like Lucas are more able to support Mike the way he needs bc they see Mike as he is and not what they want him to be. Mike does not pretend and will not pretend just to be in a relationship, if he feels deeply it would show and it doesn't show in rhe show for Will. Mike would not like Will bc he would know that Will would not be able to keep up with him.
Also like seriously, Will as Mikes type. Id we want to say Mike had a puppy crush on Eddie (which I hate that hc) wouldn't that make Dustin more of Mikes type bc Will is not punk he's basic unlike Dustin.
His "type" is anyone who can match his personality and drive which is why I always say the rest of the Party makes sense for Mike bc they are more like him than Will ever will be.