By Diane Brauner on September 13, 2016

AppleVis shares a detailed article about the new and changed accessibility features in iOS 10. The article covers:
Mainstream Stuff Impacting Accessibility:
SiriKit, automatic image descriptions, Home to Unlock, VoiceMail Transcription and Raise to Wake
VoiceOver:
Moving apps rotor command, Customize VoiceOver pronunciation, new VoiceOver voices, VoiceOver Settings - expanded and reorganized, added VoiceOver sound hints, and Mail app display changes
Braille:
Braille command for 3D touch, spoken feedback for contracted braille, and Braille readers can now access name of wireless network
Low Vision:
Magnifier added
MIsc:
Choose words, sentences or both for Speak Selection, Typing Feedback (without VoiceOver), and changes in Setting categories
Hearing:
New set of features for TTY users!
Note: This article was dated on Sept. 13, 2016 just prior to the iOS 10 release; it does not cover known bugs or issues.
UPDATE: After iOS 10 was publicly released!
AppleVis shared a new post, Apple Releases iOS 10, Bringing a Range of Enhancements and New Features.