I wonder if it's somewhat related to the "can't connect to wifi" bug that I experienced with my AW. I had to forget the wifi network on my phone, then reboot and joined again, and somehow my AW recognized the wifi and it connects now to it when the phone is away from the AW. I did re enable my facetime settings but that didn't fix it.
That still doesn't explain why the wifi toggle is missing for some of us.