Promethean Knights... Living or Machines?

The knew vidoc “Return of the Forunners” shows some great insight into the campaign. However up until this point I had assumed the knights were AI but the video suggests that they are living. I am utterly confused, what do you think?

Let’s move the discussion here please:

https://forums.halo.xbox.com/yaf_postst112921_NEW-VIDOC-IS-HERE.aspx