Follow the instructions mentioned in ZBX-18386 but assign a template to the host prototype.
Result is that when interface gets removed from the parent host - the discovered host keeps the interface with the warning like:

Cannot delete "SNMP" interface on host "hostprototypeeth0": the interface is used by items.

This is a problem since the parent and discovered hosts now have inconsistent interfaces. It looks reasonable to forbid user from deleting such interface on parent host in the front-end and warn a user about dependencies.

Similar scenario includes writing a triggers that checks an item from another host. If that host is deleted - trigger is deleted as well (without any warning it seems). There should be at least a warning in such case.