That’s how D’Addario describes ’em:
I’ve used them and it’s preferable to gutting a 12-string set (IMHO).
My favorite place to use Nashville tuning was on an old dreadnaught I rebuilt many years ago that was kind of fragile. A former owner had shaved the braces way too far, and it couldn’t take full string tension. Even with the rebuild, it was not really good at full tension – kind of tight – but Nashville sounded great.