Well, Sakurai's opinions often change. Just look at Villager, Miis, and Pac-man: all three of them were rejected Brawl characters that made it into Smash 4 because Sakurai rethought the way they work. Sakurai loves to revisit ideas he couldn't previously get off the ground, such as Final Smashes and 8-Player Smash. Ridley's chances at being in Smash Switch come down to a coin flip: if Sakurai still thinks he's too big, he's not getting in. Likewise, if Sakurai has changed his mind about Ridley's size, he's almost certainly getting in due to the fact he has everything else going for (popularity, relevance to his home series, moveset potential, etc.).