Sonos has confirmed that it won't be making a Windows Phone 8 or universal Windows 10 app. The company notes that while it is big fans of what Microsoft does, and supports a number of its services already, a decision had to be made on where to place bets going forward.
From a post in Sonos' community threads:
In the end, however, we've made a decision that Sonos is not going to build a Windows Phone 8 app nor are we planning to build a Windows 10 "universal" app. We'll of course continue to support the Windows desktop controller. We're big fans of the work Microsoft is doing across many areas, including mobile, voice control, AI, VR and of course the Groove music service, available on Sonos.
Sonos will be focusing its efforts on Voice and Paid Streaming Services for the time being. While it's not ideal to see this kind of news, it is better to have a real answer from a company than to leave it up to the imagination.
Windows 10 users looking for an alternative app to control their Sonos setup can now try out a preview version of Phonos for Windows 10 and Mobile.