For those interested (and to aid the discussion/theorizing) I re-listened and wrote up a quick quick transcription from around 6:40 minute of the video:
This is the Venli/Eshonai book, right? But really it’s the Venli/Eshonai flashbacks, and the main book is focusing a lot more on another character. This just naturally happened during the writing process. There’s another character that ended up taking a lot of the time. It’s not a person who has a flashback sequence in the books. So, you can theorize on who that would be. It’s somebody who does not have a flashback sequence. So it’s not Kaladin, Shallan, Dalinar, Szeth, Eshonai. But really it’s this character’s book mixed with flashbacks for Venli/Eshonai. … It really turned into this character’s book, a lot more than I was expecting. It was one of those happy accidents where I really liked how it turned out. But fans who go into this expecting something that’s as much Veni’s or Eshonai’s book as the last book was Dalinar’s book are probably going to be disappointed because it’s more of a split between these two characters. These three really. Venli and Eshonai in the flashbacks and then someone else in the present. … Hardcore fans, expect another character to really be the focus of this book.