Does the phone I got from full unit replacement have one year warranty?

I did a full unit replacement today -- I gave the staff my old phone and he gave me a new phone. Though it didn't come with box but I think it's new. I'm setting up this new phone but found that it shows "Coverage Expired" in "Settings > General > About".

The staff told me that this new phone has one year warranty, but this phone has coverage expired. I'm confused here. Does anyone know which is correct?