Would think that's kind of dumb. Won't they lose a ton of subscribers to Verizon?
AT&T reps are being instructed to suggest non-Phone handsets to customers. This is the claim of the linked article, and AT&T's eloquently worded response attempting to deny this just confirms that it is true. However, the reps obviously cannot force any handset upon a customer. The more stubborn reps could try to come up with lines like "The iPhone is out of stock until three weeks from now because of recent attacks on UPS drivers who attempted to make deliveries to this location, and the resulting investigations. However, we do have plenty of non-iphone handsets for you to look at!"
Personally, if I decide to purchase the upcoming iPhone from an AT&T store as opposed to an Apple store, I'm going to take copies of the article with me. When the rep starts talking nonsense, I would--very politely--shove the article in his face. If the rep acts clueless, I'll ask for the manager. Before I leave, I would distribute copies of the article to customers browsing around the store. I would promptly leave once I hear words like "sir, cops, call, police."
Lastly, I would later e-mail Apple with a grossly exaggerated account of how the evil AT&T rep tried to get me to purchase a non-Apple handset.