Yeah, I saw that tweet too. I don't mind it too much, but I know it will cause some uproar. I would rather the book be a little more slender and get a names list in a PDF or something.
As a DM I look forward to reading the section on "Falling," especially for flying creatures. Jarveena massacred the Griffons in Isle of Dread with Trip Attack, and I remember thinking that any flying creature without hover (a pretty long list) is dead meat in this game. So, I'm interested to see if they redeem non-hovering creatures a bit.