I probably should have commented on the original article here, but I pulled all of my company's production infra out of that AZ back in 2019 because AWS dragged its feet for too long deploying 5th gen hardware there.
I assumed the racks were full or something. I still don't know if they ever did get newer hardware in that AZ—I just avoid it like the plague.
I had a light chuckle this week when I discovered the work I did out of sheer frustration saved us from a partial outage seven years later.