I remember reading this article a couple months ago. Here is a quote:

This operating system is supposedly built around ads; we know how that sounds, but advertising is also prevalent in other TV software platforms including webOS and Fire TV OS. The Trade Desk emphasises a user experience that delivers “better cross-platform content discovery, personalization, subscription management, and potentially fewer (more relevant) ads,” so we hope that the importance of ads doesn’t detract from the user experience.

If this is actually true, there is no reason to consider Sonos. Especially at the super premium price of $200-$400. That makes the Apple TV look cheap.