With this said, had this been a lower end product, the SoC would probably have been an Allwinner or MTK with a soldered Realtek SDIO WiFi solution.
One of my favourite things about my Sonos setup is that it avoids me having to run bloated cloud service binaries on my personal computing devices. (Most notably, of the services I use, SiriusXM digital services have always been most unpleasant to use.)
You could VLAN them into a separate audio-devices network and whitelist their Internet access but the effort in doing that would seem to outweigh any advantages of network audio devices.
Sometimes a dumb, network-unaware Bluetooth audio sink just works...
And the fact that the module is 3rd labeled, suggests that either Broadcom or Realtek is involved