The "Google WiFi"?
> I assume they are developing more unethical uses of personal data
Why not make the same assumption about Google? They could jot down the MAC address of your device, and track you all over the place (not that they need to, since you already use Google maps).
Yes but a wifi MAC address is not my real name. I'd be more concerned if Google bought a telecom company like AT&T/Verizon and linked phones' IMEI/ESN hardware numbers to search queries. The IMEI is absolutely linked to a real identity because it's the billing address of the person paying for the phone.
The MAC address correlation seems more useful for targeted ads rather than abusing personal real names data like Equifax & Facebook.