Yep; commemorative bookplate. The covers (to my knowledge) won't be any different, but all of the books printed during the 50th anniversary are all gonna be a little special :)
I am not the one who pushes the social media buttons, unfortunately.
There are more videos coming, but I don't think we have any more premieres on the way, which was the point of the social graphics.
Forgive me if I'm repeating a known fact since I didn't scroll through 15 pages, but if you're looking for the Sorcerer article on DDB, it will be out later this week.
Regarding the Crafting video, I actually don't know. It's very short compared to the other videos (hence why it isn't being premiered), and I haven't seen it.