Leaked! Or perhaps this is just some clever marketing from Blizzard.
According to Slysssa's YouTube channel, she has scheduled a video for tomorrow, December 14, that previews a new hero and card for Hearthstone Battlegrounds. We learned a couple of days ago that a part of the mid-December Hearthstone update would include changes to Battlegrounds, enough to warrant a rating reset, and with Slysssa's track record of having Blizzard announcements on her channel in the past, this leads us to believe this 100% true.
So if we're getting a new hero and a new card, there are likely other Battlegrounds goodies coming our way too in the update. It wouldn't be too crazy to assume that additional information on those may arrive a day in advance of the patch which is expected to hit on December 15.
We've embedded Slysssa's YouTube Premiere down below which goes live on December 14 at 13:00 Eastern (10:00 Pacific, 19:00 CET). Keep your eyes peeled to Out of Cards for continued coverage of Hearthstone Battlegrounds. We'll let you know as soon as more information is available on the update.
Slysssa updated the video time since this post went live. Times have been corrected in the post and were previously 3 hours ahead of where they are now.