It really isn't that extreme. Change happens to almost all widely used languages. Just look how c++, java, js and php have changed in the last 20 years. Furthermore, the designers do not constantly throw in new stuff. The change is rather gradual, and the features that are introduced have all been proven to work in other, more experimental languages, most often whole decades after they were introduced.
C# is certainly on the maximalist end of the spectrum. It already has classes and structs and now adds records. That's at least one, possibly two, too many in my book.
But hey, some seem to prefer to have all these different ways of doing things and I'm not the one to tell them what to like or not. I don't have to use C# myself.
The proposed record types are just regular types with minimal changes to the initialization syntax. It's not like the divide between value types (``struct`` ) and reference types (``class``), which indeed have quite different semantics. You can argue that this is too much, but IMHO you need some way to guarantee that value types will behave like primitives without introducing a massive burden on the gc.