The FCC is a good source of early information on new devices that land there for their certifications. Normally when we see something pass through the FCC, there is a pretty good indication of what it is. That's not always the case, and a product that just passed through is a perfect example. All we know is that this new Google device uses Bluetooth and has a companion app.
The product is called G022A and is classified as a "wireless device" by the FCC. Scuttlebutt suggests that the G0xxx convention implies this is a Made by Google device; for instance, the newly launched Pixel 3a is G020A. The FCC ID label notes that the FCC ID and model number are displayed electronically indicating the device has no screen and that accompanying data is found via a companion app.
Specifically, the label says that the settings can be found in the companion App menu at "System - About - Regulatory." Since it needs an app to show that information the assumption is that the product is a device that goes along with a smartphone. The only spec called out is Bluetooth Low Energy connectivity suggesting that this might be a set of Bluetooth headphones, some sort of TV device, or a fitness tracker with no screen.
A TV device is an interesting possibility; Google has promised that new Android TV devices are coming soon. As for the time frame on when the mystery device might land, we have no idea. Google reportedly has a hardware event penciled in for November 17, so it may be months before we learn more.