It knows exactly what it's talking about. It understands the relationship of leaves trees and wind. It knows what a news article is. It knows what an interview is. To think that passage is a failure of GPT is incredibly obtuse.
Nothing special about 1976 in particular, but that was the first one I tried.
It lists 10 people who weren't born in 1976.
If you ask when a particular individual was born, in some cases it will continue with the lie and in others it will answer the correct date of birth.
Sometimes if you rephrase the question it will get it right. For example it listed Mark Zuckerberg as being born in 1976 but if I asked when the CEO of Facebook was born, it mentions Mark Zuckerberg and lists the correct year.
If you then ask it to fix the list, it will either list new people (all wrong in my experience) or make a shorter list with the person whose mistake was uncovered omitted.
It's probably just following a pattern it has discovered via machine learning.