Yeah, except that the software license agreement is buried deep inside the iphone, only accessible after you have:
a) opened the box
b) activated the phone through ATT
c) managed to find it: settings - general - about - scroll down to the legal section (which isn't visible until you start scrolling - and why would you given the other kind of info there - firmware number, serial number etc) and read through 50 pages or whatever of other legal notices.
Sure the customer could ask for a copy of the agreement before they buy, but who ever does that? If Apple were really sincere, they'd put up a note with the basic requirements AND legal conditions (or have them easily accessible in the store, and they would make sure that activation is done immediately. Regrettably, they're too busy selling phones to care.
Before or after, it really doesn't matter. You're still bound by the terms and conditions of the SLA. I don't recall, but I'll bet we all clicked a little box to approve the SLA during the activation process. If not, Apple should clean that up and force it before anyone agrees to activate.