I have another example of a confusing title issue that is slightly related. In my US state, pharmacists used to be "Registered Pharmacists, RPh", but increased the education requirements to the PharmD several years ago. Shortly after the educational requirement changed, the state updated the legal title from Registered Pharmacists RPh. to Doctor of Pharmacy DPharm. There are hundreds of Pharmacists with a BS in Pharmacy that are now legally "Doctors of Pharmacy."
Now THAT is confusing!