The tracker issue for the removal is https://jira.opendaylight.org/browse/NETCONF-837 and the plan of action is as follows:
1. Phosphorus SR2, due out 2022-01-27, will issue a single (mild) warning on startup. We will continue to install the implementation as part of the 'odl-restconf' feature.
2. 2022.03 Sulfur, due out 2022-03-17, will not install the old implementation by default. Users will be required to explicitly install the 'odl-restconf-nb-bierman02' feature. The warning introduced in step 1. will be updated to warn about the fact the feature is no longer supported and scheduled for removal in the next major release.
3. Old implementation will be removed from the netconf git repository's master branch as soon as the 3.0.x stability branch for Sulfur is created -- i.e. March/April 2022.
4. 2022.09 Chlorine, due out in September 2022, will not include the old implementation.
Unless serious objections to this are raised by 2022-01-10 we will execute it exactly as outlined above.