No company with any sense of self preservation would take the NES acronym. Nintendo still makes major money off that system and would sue the shit out of them. NGP on the other hand...gets no respect.

Not from Sony, not from SNK, nobody.
It was a great system with the best ratio of good/bad games since...since the original Neo Geo (probably better, really) and it lived a DC-sized lifespan.
Actually, I should mention that the one example I can think of that seems to indicate respect for the NGP on a corporate level is actually the original Warioware for GBA. Not only is it a lot like Ganbare NeoPoke-kun, but one of the characters (a big dog) seems to be wearing a hat with the NGP's "P" logo on it.
As for GCN: this...perplexes me. In a case that is exactly the opposite of the "PSX" thing, this actually is official Nintendo cannon (outside of Japan only, to my knowledge) and its really f*cking dorky. I can't believe people actually use the term "GCN" when they talk about the Cube. The acronym was actually chosen specifically to avoid confusion with the NGP (true story) which was still semi-current at the time.