“Even in season one, they hinted at that and slowly, slowly grew that storyline. I think for season four, it was just me playing this character who loves his best friend but struggles with knowing if he’ll be accepted or not, and feeling like a mistake and like he doesn’t belong. Will has always felt like that.”
Article source: https://www.huffingtonpost.co.uk/entry/noah-schnapp-confirms-stranger-things-character-wills-sexuality_uk_62d185fce4b0be7955b358ca