You could probably work out my mother's maiden name from Facebook, but I wouldn't make a SecurityQuestions.txt file and chuck it on websites I make.
I think it's noble and fair for the people behind online content to wish to be recognized if they wish, but I would absolutely abstain from putting my name in any document like a humans.txt.
At my company we have a humans.txt that is not hosted in public and we only add first names to a list. So you kinda remember who was involved over the years.
I think that is a nice touch and has no privacy issues.
At my current company, we received many phishing attempts trying to impersonate people from IT (including phone calls). LinkedIn, CrunchBase, Glassdoor, and others gives you much more data about a company’s employees. But, ironically, leaving a humans.txt file makes things easier for bots.