Apple store replacement 4s

I went to the apple store last night to get a replacement for my verizon 4s and I saw something on the phone I didn't see when I previously replaced it through verizon or when I bought the phone. When the genius turned on the phone it started on a screen that let me choose my carrier. It had a list with verizon, at&t, sprint and a whole bunch of other regional carriers. Without thinking twice I hit verizon and then walked to the verizon store to get it activated, but now i'm thinking, what if I would have hit at&t, would I now have a easily unlockable phone? or what if I scrolled all the way down and there was an option to keep the phone unlocked? I'm curious to know if anyone else has ever seen this, is there any way to get back to this screen (I don't think so)