Something to clear up; we have evidence that suggests Bayonetta was started before the ballot. However, the data didn't exist to us till 2 weeks into the ballot. We don't know if the ballot actually influenced her being playable or not.
It was already brought up that she could be worked on before being licensed(something I didn't know was possible), but we lack a lot of details to say anything for sure. While I personally believe she was chosen beforehand, there's too much leeway to show this as a for sure thing. We don't know how the licensing happened, etc.
Also, it was more of a suggestion box anyway. It was going for multiple potential characters. There's no single winner. Ridley and K. Rool, for two examples, got in due to the ballot. Numbers alone aren't the key factor, but the fact both were highly popular among the ballot still mattered. Besides that, Castlevania votes were why Simon and Richter were chosen. Sakurai also notes that Chrom and Dark Samus were added due to fan demand, which implies the Ballot being used. There's also a really damn good chance Banjo-Kazooie got in due to the ballot as part of why. So basically, there's just multiple winners, cause as a suggestion box, it wanted more to add to future Smash games as is. And this isn't even including things like Assist Trophies or Mii Costumes, many of which are popular picks or returning options(Isaac, for instance).