Dealing with Amazon customer support is such a miserable experience - it always feels like they’ve just pulled people off the street (in some far-flung country where they don’t speak native English) and given them a phone headset or given them emails to answer.
Spotify is arriving 21 Dec. You can still control Music on spotify if it has been started on the Sonos app, much the same as local music control. It's clear;y a marketing ploy by Amazon to encourage new Amazon Music Unlimited users in the lead of the the Christmas season, can't say I am surprised
Sonos have put out an update for the system and Alexa is much more responsive than previously. Especially when other things going on around the Sonos unit.
I’ve also seen they’ve knocked £50 off when you buy a pair of Sonos Ones.