Specifically, the Act required that TSA, not later than 30 days after enactment, utilize BDOs for passenger and baggage security screening, including the verification of traveler documents, particularly at designated TSA Pre✓™ lanes to ensure that such lanes are operational for use and maximum efficiency.
TSA didn't downsize the BDO force by much - probably achieved entirely through attrition and promotions. I'd really like to know how much extra pay BDOs get when they are no longer performing as BDOs. I think it's particularly interesting that they recommended the BDOs work the TDC at Precheck lanes - a nod to TSA not opening Precheck lanes because of an alleged staffing shortage or forcing both Precheck and regular pax to share one TDC.
FSDs, of course, have the final say, and as I type this, both the Precheck and regular lanes are getting longer.