If you think about it, Smash commonly runs into the problem of fizzled out finales (not BAD reveals, just......lackluster compared to the start and middle).
They may be Smash icons now, and Earthbound is one of my favorite games, but I'm not going to fault people being confused or even annoyed that the end roster of Smash 64 was Ness, Falcon and Jigglypuff over more expected characters like Peach, Bowser, Zelda, Dedede, Charizard or Diddy.
With Melee, you start with Peach, Bowser, Zelda, later Falco, Mewtwo, Ganondorf and Marth but end at Roy and Game and Watch?
Brawl fills in the required missing spots with MetaKnight, Dedede, Wario, gains snaks of all people, later Olimar, Pokemon Trainer, Diddy and SONIC, only to wrap it up with Toon Link, Wolf and ROB.
Smash 4 ended with a better group with Duck Hunt, Shulk and Bowser Jr, but they really don't compare to Megaman, Villager, Pacman.
Even 4's DLC fell into this. Popular veterans, Ryu and CLOUD. Then.......Bayonetta and Corrin......
Ultimate too with Ken/Incineroar.
So Smash is no stranger to this hype train hiccup. Right now Banjo is Cloud level. While fighters 4 and 5 are going to have extreme hype pressure on them, 4 will be more excused. 5, on the other hand, will be under crazy scrutiny, and if smash follows its patterns, 5 won't meet the hype.