Use of Blueprint overall and the ODL extension specifically is being phased out. There are is a ton of bundles in OFP which use them.
There are different classes of users:
1. Karaf CLI, these should be migrated to Karaf annotations
2. users of odl:use-default-for-reference-types=true, these should be plain removed
3. users of odl:type, which should be migrated to OSGi SCR (if feasible)
4. users of odl:rpc-implementation, which should be migrated to explicit Rpc(Provider)Service use
5. users of odl:action-provider, which should be migrated to explicit use of Action(Provider)Service use
6. users of odl:clustered-app-config, these will need to be migrated once we have an easy migration path

This obviously requires additional analysis and is a prime opportunity for cleaning up any lifecycle issues there may be.