That's exactly what I was thinking of. Cogeneration plant goes up right next to datacentre, and then various municipal services are built near that - including other factories, high density commercial and high density residential that can take advantage of cogeneration and use district heat. In particular commercial and industrial uses actually do need heat in the summer.
In some areas, natural-gas fired cogeneration only is really necessary in the winter during dark months/cold weather - which is an ideal situation to be producing district heat.
Even the grandparent's article says so if you read carefully: "A large portion of the town’s own buildings, including the municipal school, town hall, and library, are connected to the district heating network.". They didn't even attach all of the public buildings. Not to mention about the rest of the town.