That is true. I never hear what I consider to be a Southern “accent” here in central Virginia, and of course, there is not a whiff of any Southern speech in northern Virginia (a definite Yankee enclave).
Those two areas of Virginia cannot be considered as part of the South, IMHO.
As an aside, when I lived in the True South we never thought of Florida as being a Southern state despite its obvious geographic location. The Panhandle was an exception, we concluded.
Central Florida, like the Panhandle, is still Southern. We go down there for Hunting Tests for Retrievers with the Central Florida HRC. Good bunch of folks, and VERY southern!