You'd expect voice assistants to collect data whenever you control a smart home device -- that's how they work. Amazon and Google have lately been asking for a continuous flow of data in the name of convenience, however, and those device makers aren't always happy. Bloomberg has learned that Logitech and other hardware makers (some speaking anonymously) have objected to these requests for a steady stream of information over concerns they could violate privacy. Logitech has purposefully provided generic information rather than talking about individual devices, while others have reportedly asked for privacy "concessions" and have been rejected.
The companies say they need this information for the sake of faster response to voice commands as well as ensuing that smart displays have up to date information. It might be difficult to avoid sending at least some continuous information. However, there are concerns the constant supply of data could be used to piece together your habits -- when you leave for work, watch TV and go to bed. That's potentially valuable for marketing and customer research.
Google declined to comment on how it uses continuous data from Assistant, but Amazon said that it doesn't use info for advertising or sell it to third parties. Amazon isn't about to pitch sleep aids because you tell Alexa to turn on the lights at 3AM. The concern is that both Amazon and Google could do this, and that users didn't consent to sharing as much smart home data as they do today.