It looks like Sonos have shown where their priorities are: I have just received an email promoting their “fantastic” headphones, but I never once received an email telling me that they were going to do a major overhaul of the app, remove SMB1 shares or remove critical pieces of functionality from the app.
So to anyone thinking of buying the headphones - beware that Sonos are likely to screw it up when they have another new piece of hardware they want to sell, since they don't care about existing customers.