Update: the content has been re-enabled, as Blizzard announced just now.
A few moments ago, Blizzard decided to temporarily disable the new content that was released on live servers today.
This action was taken to allow the team to investigate and resolve a critical issue involving the new Xal’atath cinematic that auto-skipped for players. The new content will be enabled again when the critical bug is fixed.
A few minutes ago, we disabled the new content that had previously unlocked today.
This was a necessary step for us to be able to investigate and address a priority issue.
We will bring this week’s new content back up as soon as we’ve fixed the bug.
Thank you for your patience and understanding.