If the table sized EGC is adequate to clear the circuit with a larger OCDP, then it is adequate to clear the circuit with the smaller OCPD and larger conductors.
While the above is true, as pointed out in some installs the table sized EGC may not be adequate to clear the fault, whatever the OCPD size.
So a rule that uses the condition "if the ungrounded conductors are upsized due to VD" as a proxy for "situations where the EGC is really long and the table size may not be big enough, whatever size the OCPD is" has a technical substantiation.
However, if upsizing for VD is not a requirement, then relying on that proxy fails to satisfy the "practical safeguarding" intention of the NEC, since with the larger OCPD the EGC would be allowed to be downsized.
Cheers, Wayne