You’re misinterpreting that post. The title of the Blue post is “Classic Content Unlocking in December.” The post goes on to talk about all the content unlocking in December, with a short addendum about BWL and the Darkmoon Faire.
The entire post aside from the small mention about BWL, is about the content unlocking the week of December 10th. The phrase about an exact timestamp, refers to this post made on December 9th (Early December):
“A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second.”