I must have missed that news, that showreel is phenomenal! Linked in the comments was a Reddit AMA with the VFX creators, including this really interesting reply on their choice of Blender:
https://www.reddit.com/r/IAmA/comments/5rvwo2/comment/dddidn...
https://www.blendernation.com/2017/02/23/man-high-castle-sea...