People say a lot of things so I wouldn't take their word on anything until the games actually come out...
The one key thing I would remember when it comes to third party games is that rarely will they build their engines around the highest performing feature on the market... If they build their engine so that it only performs well on PS5's SSD or Series X's GPU or AMD's 64 core threadripper cpu, then they alienate the rest of the market. Majority of the third party games will use the most common spec cause that will be good enough for all platforms while adding some advantages to specific platforms.
With that being said though. PS5's SSD is indeed super fast and MS does have DirectStorage API for PC and Xbox as well as Nvidia is rumoured to have Tensor Memory Compression so we will see how it goes. I wouldn't underestimate PC's capabilities though...
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850
