To clarify the question can I install the latest firmware on all M580 CPUs irrespective of the product version (PV) also known as the hardware revision.
The answer is yes the latest firmware can be installed on CPUs that have earlier versions of PV. The important note is that the latest hardware version as listed in the attached file, must use V2.90 or a later version of the firmware. It must not and cannot be downgraded to an earlier version.
The new CPU PV uses a newer internal switch when combined with the new firmware provides a more strengthened cyber security platform. V2.90 introduces a number of cyber security improvements it is not clear which of these are specific to the new PV and which apply to all PVs.