adywan said:

If anyone gets any of the books can you please try it on their free PC app to see if the extra content will play? (i don't have a kindle or ipad)

Well, I've tried one of the free "Kindle Editions with Audio-Video" on the PC reader and the Android app and both of them showed a "Your browser does not support the video tag" error in place of the video.

So I guess this is true:

Kindle Edition with Audio/Video

Audio/Video content is available on latest generation Kindle Fire (except 1st generation), Kindle Fire HD, iPad, iPhone, and iPod touch devices.

I still hope someone manages to extract the videos from all three books... I don't plan to buy another tablet for them.