Why are unassigned networks in roles_data.yaml added into /etc/hosts in RHOSP and these are mapped to control plane network?

Issue

• Why are unassigned networks added into /etc/hosts in RHOSP and these are mapped to control plane network?
• Compute and controller role have different network assignment in roles_data.yaml but all networks are added into /etc/hosts. And entries in unassigned networks point to control plane network.