The API uses a portion of the EncounterTransaction contract, which I believe is not being used by anyone except Bahmni today. This is unlike openmrs-core where we expect wide usage of an API.
Also, since this is a web API, there are no compile time checks to find out dead code. We discovered by accident that we had moved out of that API a while ago.
It should probably have been deprecated, was just being more aggressive.