As the article says... "This is considerably more difficult with email because of the huge number of companies and services we want to have our updated email address. It takes a lot of time and effort to change your email address and it involves the risk of losing access to some critical service. There are so many of these services in our lives that we don’t even remember who they all are anymore!"

Including a city in the domain seems like it unnecessarily complicates things. If the goal is to provide free access to a more permanent online "identity", people shouldn't be forced to change it when they move.