I feel that a lot of people are misunderstanding the point I'm making.
I'm not saying that there's a lack of value in Olimar, Shulk, or Incineroar or they were poor ways to end or anything like that. They're all great characters. However, they aren't the show-stopping hype machines that people in this thread are expecting Fighter #5 to be. As such, given this precedent, we don't have much reason to assume Sakurai works on a "best for last" philosophy in terms of fan demand.
If Sakurai really wanted a jaw-dropper to end Brawl's pre-release, he would've chosen Sonic, Snake, or Diddy Kong for that role.
If Sakurai really wanted a jaw-dropper to end Smash for's pre-release, he would've chosen Mega Man, Pac-Man, or Little Mac for that role.
If Sakurai really wanted a jaw-dropper to end Ultimate's pre-release, he would've chosen Ridley, Simon, or K. Rool for that role (3 characters added specifically due to fan demand).
The only exception to is, like I said, Bayonetta. However, that's still only 1 in 4 times the final character has been one which was designed to get a major fan-reaction. Not the worst odds in the world, but far from something I would be comfortable betting on. I just don't want people to put Fighter #5 on a pedestal and get upset if they're not the most earth-shattering thing this side of the Mississippi, solely because they had a criterion that Sakurai doesn't seem to work on.