MS has stated that Devs are still waiting on Scarlett dev kits so any rumor based on a comparison of dev kits is a false rumor. During E3 MS and AMD have stated that Scarlett will be based on a newer architecture than PS5.
"The result is that the next PlayStation will feature custom 7 nm AMD Ryzen Zen 2 and Radeon Navi architectures, while the Xbox Scarlett will include "next generation Radeon RDNA gaming graphics architecture" as announced by Lisa Su, CEO and President of AMD. AMD has confirmed that next-generation RDNA will be based on a 7 nm+ FinFET process, which will support hardware-based real-time ray-tracing and next-gen RDNA. By contrast, the 7 nm Navi architecture will only be capable of shader-based ray tracing and current gen RDNA."
Scarlett more advanced than PS5