I'm just waiting for them to see who wins the ballot and is getting in.
In my mind, it could go one of two ways.
The first way is that the ballot was an idea of the Smash team, and Sakurai is supportive of it. This means that no matter who wins, they would have to have the Sakurai Seal of Approval to get in, even if they are in 1st place.
The other way is that Sakurai was told to do the ballot by Nintendo higher-ups. This would mean that Sakurai doesn't really want to do the ballot, but has to, because if he refuses Nintendo will tell him to gtfo and will just make another developer do it, and Sakurai doesn't want to see someone else handle Smash. Sakurai would have basically no control, and whoever wins the polls gets in. In this scenario, hypothetically, Ridley would be added toy he game as playable if he was high enough on the ballot, and Sakurai would be forced by his employers to make him.
I personally believe the reality is somewhere in between. Either way, I think K. Rool is pretty darn likely, though I have a small feeling that Sakurai may not be a huge fan, seeing as he was one of the biggest requests for Smash 4, and didn't make it in the base game.