I'm guessing they assumed he was bc a lot of neurodivergent people (especially those on the spectrum) identify with Sangwoo/felt reminded of themselves while reading ٩(๑❛ᴗ❛๑)۶
Good to have the confirmation either way (●'◡'●)ノ Btw, do you happen to know if the novel has a translation available anywhere? I only found the korean version, but thought i'd ask just in case ╮( ̄▽ ̄)╭
Main character has autism which makes everything so much worse poor lad