Apple's "HomeAccessory17,1" device is a new smart home accessory that the company is working on, as revealed by code found on its backend by MacRumors. The device is expected to be a HomePod with a screen, combining features of a HomePod and an iPad. It will be designed to control HomeKit devices, make FaceTime calls, and more, essentially serving as Apple's take on the Meta Portal.
Yes, the "HomeAccessory17,1" is expected to use the A18 chip, as suggested by the identifier name. This chip would provide the power necessary for Apple Intelligence features.
The new home accessory will run a software variant of tvOS, similar to the HomePod. There is also evidence of Apple's work on homeOS, which could be the firmware running on this device.