Notice the 3rd party DHW tank. There are ones with heat exchangers.
It might though; lots of boilers are combi systems that do your hydronics as well as on demand hot water. For example another air-to-water system that competes directly with the one in TFA:
That might make sense, but as it doesn't mention any cooling features, I assumed it was purely for (faucet) hot water. The fact that there's no tank is weird if it was for residential hot water, I think you're right that it's for heating. (or combo, with a separate hot water reserve for showers)
I think it is targeted to cold weather markets for home heating retrofits that have gas boilers driving radiators.