Are new phones updated?

Hi!
I'd like to purchase an xt907, and join your bandwagon. However, I'd like, of course, to be able to unlock the bootloader.
I noticed that many of the phones sold on ebay are already 182/183.46.15 or other updated firmwares.
What about "brand new" phones? Do they ever come updated, or is the phone out of the box generally 182/183.46.10?

thanks!