While many of the improvements made in Visual Studio 2019 are useful across different languages and platforms, there are always those changes made that are specific to individual languages. They fulfill a particular need for a particular subset of developers. Or, perhaps, the underlying structure of the language makes replication of the feature on different platforms too difficult to implement smoothly. Over time, these improvements might find their way into other environments, but, initially, they are available only in certain workloads.
A good prior ...
