No i'm saying that if a PS5 with bc can have a Zen a PS4 XY can have a Zen.
There is no difference between the 2.
Whatever possible problems/limits a PS4 XY has, a PS5 with bc has too.
Just calling your console different doesn't change reality.
Neo has a different function from a potential numbered unit as i said. Developers are barred from taking advantage of the hardware beyond PS4 levels because it is strictly a PS4. A PS5 would be its own unit, and while compatible with earlier units, would not be shackled to their legacy hardware.