Board Thread:Plants vs. Zombies 2: It's About Time/@comment-24725728-20140512192458/@comment-4009269-20140610050822

I found an identical video uploaded by Game Mob, and here's the description:

"With the upcoming Dark Ages Part 1 expansion, players will battle medieval zombies in the dark of night. Witness the return of fan-favorite plants Sun-shroom, Puff-shroom, and Hypno-shroom, and the debut of the brand new Sun Bean. Do battle against a plague of new zombies including Knight Zombie, Jester Zombie and more."

So I guess Dark Ages is arriving in parts. Maybe part 1 only has the plants mentioned above, and the other ones we found are in part 2 or 3 (if there ends up being that many parts).