For example, if someone doesn't use discord or discord won't let them join with certain email addresses, how would that person contact staff if they couldn't access MangaDex?
Edit: Somehow I forgot about the community menu at the top.
I just tried to find anything you mentioned and it wasn't easy. "Follow mangadex" section on front page doesn't help because it's very plain and easily lost between other sections.
Add "Contact us" into "Info" menu in top bar for reference. Would be more intuitive IMO.