Odd. You can put a 500hz monitor on any rig/gpu. You can put a playstation one, on a 240hz monitor, if you want. Maybe you arent understanding what they are saying, or they didnt understand you. Show us the email you sent them, and their reply.
(using a 7900xtx, and a 6800xt on 2 samsung G7 240hz monitors just fine, basically the same release date)
Something isnt adding up here.