Unlocked iPhone replacement?

[space-time]

my ATT iPhone is out of contract and I was able to unlock it; the iPhone is now pregnant (i.e. battery is swelling), and I plan to try my luck at an Apple Store to see if they replace the battery. I heard that in some cases they replace the entire iPhone. In that case, do I need to point out that this is unlocked? I would like to get an unlocked unit if possible.

Thanks