Maybe they don't think it's much of a spoiler ... I think a lot of what they said prepared us to expect it. At NYCC Jen said it was nice to play a villain "for a little while" so I'm not too surprised ... and they knew that fans were there taking pictures so I think in a way they just wanted to control the spoilers that come out. And Adam retweeted the picture ...
I'm intrigued about what this necklace that Emma appears to be wearing is:
