We aren't getting anime characters. It just isn't happening, and frankly I think most Smash fans don't want it. The errors in thinking here are multiple:
1. It's not about what a character's first appearance is. It's about what a character's most significant appearance is. Is Goku more important as a character in Dragonball Z or as a character in Dragonball FighterZ? That's not really a question; we all know the super obvious answer. If this is a hard idea for you, think about it this way. For any character, imagine you absolutely must consider only one form of media in which they appeared and must call every other totally insignificant. Can you possibly say Goku's anime appearances are insignificant to who he is? Since the obvious answer is "no", he's not a video game character.
2. The criteria is "video game character" not "video game software character". R.O.B. is a video game hardware character. He's very literally a NES accessory; that is not even questionable in terms of being a video game character unless you don't think the NES is a video gaming machine. A LABO construct would also be "valid" as a video game character too; it's the same idea. 100% of Smash characters are unambiguously video game characters; there are no even vaguely borderline cases nor will there ever be.
And while we're at it, no, Sakurai could not put Goku in if he wanted to. Licensing for a character like this is insane, and while Nintendo could afford it (they're rich), spending "five times more than we spent on the licenses for every other piece of third party content in the game put together" wouldn't be appealing to them. I'm pretty sure if Sakurai were somehow inflicted with the temporary insanity required to put a non-video game character in Smash, he'd get vetoed by his bosses at Nintendo corporate on this point. It's actually impossible, and in fact, we've basically been told this directly. When they were announcing the results of the ballot and announcing Bayonetta, you might recall they made it clear that several characters who were not "realizable" were suggested to have done pretty well. This is probably anime characters and other not video game characters; I'm sure Goku, Batman, Bart Simpson, and Barack Obama did pretty well in the ballot, but they're all not happening and honestly it's silly to imagine otherwise.