I know the "PS5 will struggle in third party open world games" is attributed to Chris Grannell in the RDX podcast with timdog and eastwood. The "ex-sony-dev" who appeared out of nowhere on the runup to console launch then disappeared into obscurity again when they launched. He can be attributed to most of the silly quotes. He even said stuff about no raytracing and hearing about staggering differences between the consoles.
The guy was getting 3 threads on the same subject on
neogaf and web articles quoting him.
There was this other "dev" doing the rounds too that had an account on neogaf but I don't recall what his name was. I know that he used "Blur" as possibly a game he worked on in some capacity and maybe in his avatar/username but then distanced himself from the game by not mentioning it anymore and started using his real name in interviews. He created his own blog site saying how PS5 is weak and Xbox will crush it. He was full of this type of nonsense quotes too. He was always an XB1 defender even prior but during next gen launch some articles started quoting this random guy. Anybody remember the name? I remember I got in to a lot of back and forths with the guy on neogaf.
Edit: the other guy was Gavin Stevens "Team Blur Games". O'dium on
neogaf