I don’t think it helps with basic model creation or detection speed / accuracy. But I’m sure it helps guide Sense as they invest in refining models based on specific devices they see used in their customer base.
Here’s the announcement about the introductions of Home Details:
Under Settings > My Home > Home Details, you can now tell Sense more about your home, as well as filling in information about which devices you have. This information will help Sense improve device detection over time with some helpful clues, but in particular the postal code and square footage information will be used for the similar homes comparison mentioned above. Over time we do plan on using more than just square footage and postal code, so this is just a starting point.
I’m hoping that some time they link it to this database to add in Always On info