Watching Apple's moves in this space, transferring Apple TV's functions directly to third party TVs and others to HomePod I believe that there's a good chance that HomePod is going to become the centre of the home, taking over that capacity from the AppleTV.
AppleTV is progressively becoming software rather than hardware. This was confirmed in the renaming of the TV app to Apple TV and the service as Apple TV+. Apple has worked with major TV manufacturers to get AirPlay on all TVs going forward and as we can see here, they're building in depth HomeKit and remote app support and have also announced that the Apple TV will be available on TVs as an app.
Further fitting this strategy is that Apple is downgrading the importance of tvOS' home screen in favour of the Apple TV app. Pressing the Home button on the Siri remote now takes you to the Apple TV app, not to the Home screen. Unlike tvOS, the Apple TV app is self contained which enables it to be easily ported to third party manufacturers.
HomePod has already taken on the task of being a HomeKit hub from the Apple TV. It already plays Apple Music in your home and works as an assistant as well. With Siri Shortcuts, Apple has enabled developers to put their iOS apps on HomePod.
Now, what if it could take commands to play TV shows and movies on a TV? "Hey Siri, play Star Trek Discovery in the living room". Well, it just so happens that in iOS 12.2 Siri on iPhone and iPad became capable of doing exactly that. When the feature comes to the HomePod, you won't really need to have an Apple TV if your TV either supports AirPlay or has the Apple TV app (or both).
In the Fall when AppleTV+ is launched, I expect this strategy to tie up loose ends with perhaps an HDMI AirPlay stick + remote to be released for those without AirPlay enabled TVs or who want to use a tvOS UI and Siri remote with their TVs.
Today's HomePod price cut is another important step to build on this strategy as it becomes the device you purchase instead of an AppleTV and needs to be affordable. The current model Apple TV is $199. At $299 for an Apple TV replacement, a premium speaker and access to thousands of iOS apps via Siri Shortcuts, the HomePod starts to make a lot more sense.
RIP hockey puck Apple TV (sometime this Fall).
While a lot of this does make sense, with Apple's Apple Arcade coming with exclusive titles from studios coming, if it becomes somewhat to definitely a hit for them, they won't stop tvOS development for those titles. Apple still wants a slice of console gaming and they actually made quite a capable little device in the Apple TV 4K for that. I believe Apple is just finally getting smart about the living room and trying to cover all the bases to increase their possible market share with TV+ and the TV app after languishing with the living room for so many years.