I've got a suspicion that the claim of Apple sending the AirPort engineers to
"other product teams, including one currently working on Apple TV." which was about 7 months prior to the Home Pod being announced at WWDC.
Think about the similar technologies that they can offer with products like the Home Pod.
From Apple's page about the Home Pod:
Seven tweeters. Amazing sound from every angle.
"HomePod has a unique array of seven beamforming tweeters that precisely focus the sound, from very narrow beams all the way to true, consistent 360º audio. By aiming those beams throughout the room, the tweeters create an immersive sense of space — no matter where HomePod is placed or where you’re sitting."
Although we haven't seen a consumer-ready unit, I wouldn't be surprised if there were ra few RJ-45 jacks on it somewhere. This would allow them to make it perform double-duty as a router. It already has WiFi capabilities, obviously. And with them promoting the idea of having multiple Home Pods to get better music sound throughout the house, that could also become Apple's implementation method of a "Wireless Mesh" offering.
I hope I'm right. I love not having to reboot my AirPort Extreme router, or having to explain to someone else to power cycle the router in order to make it come back online like I had to with previous routers.