There is no difference that I’m aware of for the basic energies. I remember this thread (No Rarity Base set Japanese 1996 complete or not) from a while ago when I was similarly curious.
Re: CGC, I don’t think they’re doing any provenance checking. I think they just used to slab all expansion basic energies as no rarity. (There are a bunch in the pop report). I think they stopped doing it at some point though