Yep, as usual, it's the FAA's fault.
"Since publication, the FAA received 10 comments from individuals requesting that comment period not be extended. The FAA has also received requests from Aircraft Electronics Association, Aeronautical Repair Station Association, Aviation Suppliers Association, Aviation Technician Education Council, Helicopter Association International, International Air Response, Inc., Modification and Replacement Parts Association, and the National Air Transportation Association to extend the comment period by an additional ninety (90) days. These commenters requested more time to review the proposed rule and associated guidance documents, and to develop comments and recommendations."