RWS 54 Laminate Pro

Was getting ready to purchase the new RWS 54 Laminate Pro. After talking to the folks at Airgun Depot and Pyramydair they told me if I added a sling swivel to the butt of the rifle it voids the warranty. RWS put a sling swivel on the front so I guess if I want to use the swivel to mount a bipod that’s okay but if I want to add a swivel to carry it while hunting that voids the warranty. To me that is “NUTS”. Why should a sling swivel void anything.