That's a terrible argument. "He's not a playable character" or something is an acceptable argument, things often get in because they're new. Look at Lucario.Not very likely. He's a bit too new, unlike the elderly Pikachu.
When SSBB came out, Lucario was as new as N is. That's......really not an argument.
"He's not notable enough"
"He's not playable in any game"
"SSB has a tendency to ignore almost all Pokemon humans (since Melee just got a few random trophies and Brawl had Red)"
"Too much competition from actual Pokemon"
"Too many 'swapping' characters (Zelda/Red)"
All of those are acceptable. Anything else is pretty much null. I can understand people thinking he doesn't have much of a chance, but your apparent reasoning is just terrible, no offense.