Actually Brawl model importing using Brawlbox came to fruition about 5 years ago, 3 years after Brawl was released, and people had already been able to import basic unrigged models a little bit before that. So if you think about it, non-complex model imports after 2 years since Smash 4's release isn't too odd, we're just old af and have been through some [censored].
And from what I've heard, Smash 4's NUD model format is apparently a lot easier to manipulate than MDL0 was.
How is Smash 4's NUD Model format easy to manipulate?