That's good news.
This thread Gigabyte Z390: Disabling C-States is a different motherboard than yours (and asking about a different issue), but user terabyte explains, "Intel CPUs have a built in feature to disable some of its cores when they are not being used and this is exactly what C-states do. If you disable C-states none of the cores will go to sleep and there will be a lot less fluctuation in the amount of crrent flowing through VRMs resulting in less or no coil whine. Some people disable C-states because they think these are meant to be used in laptop where power saving features matter and there seems to be a general understanding in Overclocking community that C-states should be disabled on Desktop PCs to get better performance."
I would not think there would be any significant difference in power consumption, but that may also depend on the type of work you do.