It's a doorbell camera. Who cares if it's HomeKit, Alexa or Google compatible as long as it has the app. You don't need to set scenes for doorbell or turn on/
HomeKit support should make it possible to view the video straight from the notification, without any time wasted waiting for the app to launch. It should also bring Apple Watch support and the ability to do stuff like turn on the porch light if the doorbell is rung, or motion is detected. (less)