That suggests we're looking at a permanent price cut here, a theory corroborated by AppleInsider
after verifying it with several unnamed company employees "not authorized to speak on behalf" of Apple. These types of reductions are usually reserved for older products following announcements of new generations, but even though the HomePod was formally unveiled in the summer of 2017 and commercially released in early 2018, we haven't heard a single credible rumor regarding the development of a sequel or spin-off lately.
In the meantime, it's definitely worth highlighting that the HomePod has a new price tag attached to its name outside of the US as well. In the UK, for instance, it costs £279 ($365), down from £319 at launch. Canadians are asked to pay 400 local bucks after a $50 discount, while the French and German tags have been slashed from €349 to €329. That's at least as far as the official online Apple Store is concerned, because third-party retailers might be able to occasionally cut you significantly better deals.