What you are outlining is about what happened with PS5 having only RDNA1 and XSX using 'true' RDNA2. Now what actually happened is Sony used the most important RDNA2 feature (hardware accelerated intersection RT) and ignored the rest (the "RDNA2 hardware VRS") because they knew game engines wouldn't need it. And they were 100% right as history proved. RDNA2 hardware VRS is an half-baked feature (textures get blocky, now way around it) and devs actually have better results by doing their own software implementations (COD), and avoiding blocky textures by specifically not using the new hardware block.
And the fact that MS already announced they wouln't do a mid-gen console should be another hint of them knowing that "true RDNA 4" features wouldn't be enough to counter PS5 Pro console which will supposedly (from leaker and patents) use similarly the most important feature of RDNA4: hardware accelerated ray traversal.
It's not really the same since MS wasn't in a place to take advantage of any additional hardware features that the xbox series might have over the ps5. The ps5 is also the lead platform since the previous consoles have sold more than double what ms has and the current console is double. We may still see advantages in the series consoles over the playstation 5 as more of MS's games come out specifically targeting that hardware. All the games that have come out or will be out started development on previous consoles and in some cases like starfield are 8 years in development.
You'd have to believe that the changes between rdna2/3 and possibly beyond rdna 4 (since we are talking 2026) would be insignificant. We already know that ray tracing is extremely poor on rdna 2/3 and we don't actually know if or when AMD will be able to fix that .