Can't enter Shattered Halls or Steamvaults at level 64. Ninja Hotfix?

It would seem that players can no longer enter Steamvaults or Shattered Halls at a specific level as of a silent hotfix this afternoon. I was in there getting carried by my guild on a level 64 alt and I got disconnected and when logging back in it says "You must be level 55 to enter this instance". This happened to a few people I know on other servers as well. Leaving group and entering, forming a new group and entering all caused the same error message.

I haven't seen anything official yet. Does anyone know what the new level requirement seems to be?