First I can tell you that this is NOT true at all. I worked at At&T for 5 years and left in MAY for better schedule. However I can tell you the employees are getting first dibs, there is NO doubt this goes on. ALSO I can tell you that the Managers set aside a certain amount for OBF's that may occur. They need to have those sitting aside for escalations.
I can tell you for sure employees are not able to purchase the iPhone 6 at this time. Maybe there are one off's but company policy is that they can't. They may have put them aside for frequent customers, business accounts or for friends but not employees themselves.