"This allows Sonos to detect your nearby speakers during the Setup process. If you leave this disabled, you will not be able to setup your speakers."
The iOS explanation that it's only used to auto-fill a zipcode is insane and presumably inaccurate, given the Android permission's description.
Putting the blame for this on Apple/Google doesn’t excuse Sonos’s sleazy data collection here, of course.
Looks like a case of coarse grained access rights required to enable very specific, time bound setup features, but then again that’s what the underlying platforms ask for/provide (like, 5min BLE beacon requires location access, which also grants GPS)
Not being able to complete setup without it though is not OK.