The Answer depends on WHERE you preordered the iPhone.
A) If you went through Apple Store (app or website), Verizon, Sprint, and AT&T models required input of wireless account phone line info (even if you Paid in Full). These units will require activation lock removal with the associated phone line billing info.
B) If you reserved for Apple Store pickup, likely same scenario as above because Verizon, Sprint, and AT&T models required input of wireless account phone line info (even if you Paid in Full) before you could reserve for in-store pickup.
C) if you preordered through Best Buy, Walmart, or Target, their iPhones are subject to the Reseller Flex Policy.
https://forums.macrumors.com/thread...bject-to-the-us-reseller-flex-policy.2006324/
D) if you preordered through wireless carrier website (i.e. Verizon, Sprint, and AT&T wireless directly), the iPhones likely follow the individual carrier's unlocking Policy.
E) Exceptions to A and B above is T-Mobile iPhone model.
EDIT:
F) Come 11/3/17, if you are among the first to camp outside a physical Apple Store and can buy an iPhone X paid in full, then there should be no activation verification tied with the store bought iPhone X (Verizon, AT&T, or T-Mobile model). Not sure with Sprint variant though.