What Happens to Warranty Cards?

[NYC2023]

Apologies for the basic question- somewhat new to this.

When a grey market dealer sells a recent (last couple
of years) watch with no warranty card/papers, what happens to that card? I totally get this happening on a 15 or 20+ year old watch, but it seems highly unlikely that someone wouldn’t have kept the papers on a brand new Rolex, particularly when they still have the box (“box no papers” watches).

Is there something shady that goes on here like reselling or altering the cards?