I'm not sure this change really affects the HomePod - I've heard from some Siri still can't (or won't) play music from Spotify when asked, and defaults to Apple Music. This goes for in-line controls on headphones/earbuds and in-car control. If music is already playing it seems to control fine, but if trying to start playback it opens Apple Music. I'm getting this second hand so I could be a bit off but that's part of the reason my SO moved to Android.
I guess that is the reason I got a firmware update enabling Spotify Connect for my Denon receiver the other week. It had some old pre-Connect thing previously.