More than the
residential use of some entire cities.
This is a misleading comparison. "AI data centers" aren't a residential use, they're much closer to an industrial one, and they should be considered on that basis.
In comparison, a 2007 report on the US Aluminum industry (https://www1.eere.energy.gov/manufacturing/resources/aluminu...) (aluminum is a particularly heavy user of electricity, since its main processes are electric-driven and not chemical/combustion like steel) notes that the US industry used 90e9 kWh/yr in 2003. That's 10GW of power on a continuous basis, comparable to the data center usage discussed in the article.
An exact comparison is more difficult because the article discusses a number of individual projects, without aggregating them over time.
Is this projected energy usage good? I don't know, but the statement that "AI will be as important to the United States as the aluminum industry" doesn't seem too outlandish.