FAB-12982 changed the meaning of requiredPeerCount and maximumPeerCount in private data dissemination.
FAB-12982, it chooses 'required' and 'not required' peers statically before attempting to disseminate. That's not the intent of requiredPeerCount. The intent is that an endorsing peer tries to disseminate to <maximumPeerCount> peers, and you need dissemination to succeed for at least ANY <requiredPeerCount> of them for endorsement to succeed.
The current implementation of statically picking required peers will result in more endorsement failures than expected.