I found out about this change yesterday. We're working on finalizing the documentation/notice and getting it published. I didn't think any of the new shipments were going out yet!
This document includes a listing of HW Revision Levels that include the bracket (p/n 37201) so you can identify which ones include it in the box. Here's that table: P/N Description HW Rev Level
31028 AP3915i-FCC 908754-10 AF
31029 AP3915i-ROW 908755-10 AG
31031 AP3915e-FCC 908756-10 AG
31032 AP3915e-ROW 908757-10 AHI'll share the full document in this thread when I can.
I recently got 50 and the one I opened has the mounting bracket, so I'm guessing they've added it. The serial numbers all start with 1824Y, what do yours start with?