Hi! That was a very interesting piece of information. I googled up Duden but was not able to find relevant information.
Can you point me to more information about this?
This is one of my hobbies, learning about standardization of old languages via “new” media.
For example, before Radio most Italians could barely understand each other. However when Radio chose the Florentine pronunciation, all of Italy slowly standardized to it.
Look at China, where now the Mandarin pronunciation rules are “killing” regional dialects
In India, the Bombay Bollywood Hindi has become the standardized Hindi
In our own United States, we have moved progressively towards a Mid-west accent, as our TV broadcasters have favored that accent
When I was a child, accents found amongst members of Congress were marked. A Californian (as I was at the time) could barely understand a Kennedy from Massachusetts, or some of the Southern Senators. I remember my uncle (when he came home from WWII) talking about the boys he knew on his ship from "Joisey" and how they couldn't say dirty bird (came out "doity boid"). Fritz Hollings from SC was one of the last Southern Senators who talked as if he had mush in his mouth. But now, the accents have pretty much evened out; and you can barely tell which state they are from unless somebody posts their name and state on the screen.