Is a factory new Nissan engine called Remanufactured?

My mom just had the 2.5 engine in her 2002 Altima replaced by a Nissan dealer who insists that it's a factory new engine. However stamped right on the engine it says Remanufactured and it also says "Reman Engine" on the sales receipt. I questioned the dealer and they said that it is brand new and that Nissan calls it "remanufactured" because it has upgrades since the original engine in 2002. I asked "Has the block or any part of this engine ever been in another car ever?" She said "No. It is totally brand new. Your mom's insurance company would never allow us to put a remanufactured engine in her car" (the insurance company is paying for the engine because of the accident that caused the engine to get ruined).

Is it really true that Nissan sells brand new engines, but stamps them with the word "Remanufactured"? Do they also sell actual remanufactured engines and if so, what do they call them? This doesn't sound right to me.

Thanks,
Rich