insurance device replacement

My wife’s iphone x back glass was damaged. We have insurance, according to which we gave it to the official representative office in Estonia - Valgeklaar. They say what device will be replaced by the new one. But warranty of the new device will be only 3 months and explained this by saying that for Apple it is like replacing a spare part.

It is true?

Also I heard that all iphones x have problem with displays and they all need warranty service?

and the last question about replacement device. It must be absolutely new one or it will be only device without original package (that may be recycled)?