I disagree.
My parents owned a grocer's shop and we sold oatcakes, and when someone asked what they were, we would always say "Welcome stranger …" and they would be surprised that we knew they were from outside the Potteries.
Our explanation was simple - if you live round here, you know what those are!
Plenty of people from outside the Stoke area had never seen oatcakes before, and I think that still applies now.
You can go thirty miles in any direction from Stoke, and find masses of people who don't know what an oatcake is.