Who is responsible for adding a new amendment to our policy which excludes all transgender transition coverage?

On January 1, 2017, our policy included coverage as was required by  section 1557 of the ACA. On February 1st, 2017 a new amendment was added to our policy which subsequently rendered everything related to gender dysphoria and gender reassignment surgery to be excluded from coverage. I need to get a straight answer... who initiated the adding of this amendment? Did BCBSTX add it themselves, all on their own accord with no request for such coming from my employer? Or did my employer specifically ask that this exclusion be added to our policy.  This is a simple question which deserves a simple answer. 


If BCBSTX initiated and executed this change, why was and is there still no announcement of such to be found anywhere on the Internet?