New York’s First Electric Skyscraper Promises Luxury With Lower Emissions | An apartment tower in downtown Brooklyn has ditched fossil fuel heating and appliances
Most electric heat pump hot water heaters have a slow-mode which uses the heat pump, and fills a large tank with hot water, and a fast-mode which uses a resistive heater when the tank runs out. I don't see why this situation is particularly different for larger buildings, except that they need a larger tank and an electrical supply which can deliver the needed wattage.
Cheapo landlord could of course install an undersized unit, as they can with any other key system.