I’ve seen 2 people buy previous iPhones models that were not Telus customers. This was not on launch day though. They didn’t even give a phone number. One guy was picking up a new phone for his girlfriend on Telus (didn’t give her phone number) and the other person was just rude and didn’t give any reason, just demanded a phone. I don’t know if this is still something Telus allows. At the time, Telus full priced phones were $50 more than Apple retail price. We don’t have an Apple store where I live though.
You’d end up with a phone locked to Telus though. Currently, Telus requires the phone be on their network for some length of time before they will unlock it.
Not sure what would happen when the December 1 guidelines comes into play though. Maybe if you hung onto it until then they’d have to unlock it for you.