IANAL but even though their statements are "in public" but I doubt either of them would qualify as public figures - that is reserved for politicians and such.
That being said, spez here seems to have actually slandered iamthatis. This occurred when when spez claimed that iamthatis was "blackmailing" reddit for 10M$, which incidentally lead iamthatis to post audio recordings proving that spez was lying.
Maybe I've got some of those details wrong, so correct me if I am.
DLSS over ray tracing? hah, no. The technology purpose are completely orthogonal to each other. Ray tracing is about adding more accurate details while DLSS is about adding a blurry mess in exchange for higher frames.