In v5.0 there was a routing table refresh+wait for flush right before releasing the critical section in rename participants. That code snippet (or something similar) should be reintroduced because it is a way to ensure that both primary and secondaries will update their filtering info for source and target namespaces, properly reacting when a stale router tries to target them.

Instead of simply refreshing, a better way would be to force a metadata refresh + setting the new filtering metadata as currently done by the collmod participant.