Themes and Theme voting are currently on hold as the Instructure Product Team works on implementing a better solution to collect your feedback. Read Ruth's blog for more information.
I hope Canvas has been working on this since it is over 1 year since we have brought this to their attention. We are getting continued pressure from faculty and students that are wondering why captioning is not available in the audio/video features in Canvas. As Venitk mentioned, the learning curve is steep to get students to use a third party and then upload their posts or submissions with captioning. It should be an embedded feature in the RCE.
