AMD almost certainly knew about it as it's in DirectX. This standard, called DirectX Raytracing (or DXR for short) is actually what the very first game to ship

AMD almost certainly knew about it as it's in DirectX. This standard, called DirectX Raytracing (or DXR for short) is actually what the very first game to ship with real-time raytracing uses. This is what Battlefield V is using. Not Nvidia's proprietary extensions. Since nobody pushes to add a fancy new thing to DirectX unless they plan to ship hardware specifically to do that new thing, AMD would have to have been blind & deaf to not know Nvidia was going to ship RTX this year.