How to disable faces/people recognition in iOS10?
Apple did not give us a way to opt-out of the image analysis and the only way to avoid it is to move your photos off of the iOS device.

Maybe good to know. All image analysis is done on device and never leaves your device.


  Apple’s system is more focused on privacy than Facebook's or Google’s,
  with stricter limits on how the data is collected and stored. Onstage,
  Federighi insisted that Apple’s new system only uses local data, which
  means the company isn’t storing faceprints on company servers — a
  crucial point for anyone worried about their faceprint being used for
  more than just cataloging photos. Faceprints are still being created
  and used, but it's all happening on your phone, where Apple and the
  rest of the world can't access it. That’s different from Google and
  Facebook, which store data on the cloud and get significant scale
  benefits as a result.


Source: Apple's new facial recognition feature could spur legal issues - The Verge

What you can do to ensure more privacy is to not name the detected faces and to merge all detected faces into one single people album. This will prevent Photos from identifying more photos of the same persons.  Then hide the people album. Then the persons will not be used in Memories.