I know little about ArcSystem but I praise the logic in this statement. I wish people would apply this logic to other third party companies as well.
Like saying that Steve would deconfirm Banjo Kazooie.. or viceversa. Is like saying that if crash Bandicot makes it in, i'ts imposible to have a Overwatch character...
It can be argued that sometimes this applies, for example, if we get Sol Badguy, i don't think we are getting Ragna, or viceversa, but this is usually teh exception, and is because the characters are related to more ways that just the copyright holder.
If Crash comes in is because he is Crash Bandicoot, not because Activision / blizzard NEEDs a rep. Same with Overwatch character. Banjo came in not because Microsoft needed to be represented... but because is Banjo Kazooie.
Copyright holders can be an issue ... (square enix, Konami during smash 4? Anything Sony) but usually is more of a hurdle than an goal or an objective, and right now there are very few companies that would want to hinder the inclusion of something from them in smash.