That was the joke. The author is delightfully subtle.
I worked at a big company that assigned its summer interns to write an online sarcasm detector. At end of summer, they announced they had been completely successful. No one asked for evidence. Clearly the students had understood the assignment perfectly.
Anyway, it was said that this had been assigned. I never spoke to anyone actually involved. Or, admitted it.
I wouldn't say that YAGNI is the counter-slogan. Rather, it's the overarching principle. It's not going to change. You aren't going to need to code for that contingency.
Often the best way to design for change is to make it easy to edit the code, test it, commit, and deploy, but not everything is a web app.
[1] https://martinfowler.com/bliki/Yagni.html