It's not a new technology, though. The Vancouver system mentioned in the article has been in operation since 2010, which may be a short time in infrastructure terms, but similar systems that extract waste heat from sewage have been in commercial operation since at least the mid-1980's. The system in Vancouver is now being expanded to 9 MW of power output, but there's a similar one in Stockholm that first opened in 1986 that now has an output of 225 MW. That one uses treated wastewater though, while the one in Vancouver operates on raw sewage that hasn't hit the treatment plant yet.
District heating is at a different scale in northern Europe and especially in Scandinavia. The systems in North America are (with a few exceptions) typically local to a campus, a neighborhood or a small downtown area, serving maybe a hundred buildings with maybe tens of kilometers of pipes. The public heating utility in Stockholm alone serves 800,000 people, has over 3000 km of pipes and generates over 8,000 GWh of heat energy in a typical year. It's kind of the default way of heating most buildings, here. The main exception is single family homes where past eras of cheap electricity often made people prefer other heating methods.
Such systems don't have to be huge to be useful, but the bigger they are, the more opportunities you have to move heat from places that don't want it (data centers, industry in general, etc) to places that do.