There are two fronts on that matter.
One the PS5 CUs lack hardware lower integer and precision that makes them not RDNA 2 CUs... so seems to be less credible.
Other that says PS5 CUs have the hardware lower integer and precision because they are based in a internal "RDNA 1.1" that is basically identical to RDNA 2.0.
I can add a third option... Sony asked AMD to remove the hardware lower integer and precision from the RDNA 2 CUs making them Custom.
And there is no dedicated chip for ML support it is just the CUs with lower int and precision supports.
The pic below shows the difference between them.
RDNA 1.1 and RDNA 2 that are identical supports ML.
RDNA 2 not.