I doubt he cares, since the Ridley support in the east isn't exactly what it is here, and He did the same thing with Yellow Devil (whose role is still unconfirmed) Sakurai 's never given much attention to Ridley, let alone plan an elaborate reveal process for him.
Are you serious? Yellow Devil was shown right off the bat in Mega Man's trailer in the Dr. Wily stage. Whether or not it's a boss fight or a stage hazard is unknown, more likely the latter, but the point is that we're immediately shown footage of it not being playable. Same for Nintendog, which acts like a giant looming in the background of its stage. Even Cragalanche, who Sakurai mentioned in the description of one of his Kid Icarus Uprising stage screenshots, had an immediate, literal "Not really." to his statement of maybe being a stage hazard.
Compare those to Ridley. We have not seen a single bit of Ridley thus far. There's no reason why he wouldn't just tell us that Ridley is a stage hazard or not like Cragalanche. There's been not a single bit of footage or screenshots to show that Ridley is a stage hazard. If he was a hazard, Sakurai has been
deliberately giving us angles where we cannot see him. Does that not come off as suspicious to you? Whether or not Ridley is playable, it's a fact that Sakurai is definitely giving Ridley attention this time by teasing us about him with none of the detail equivalent entities like Yellow Devil or Nintendog have gotten.
Like I said before, there is no reason to avoid showing us Ridley unless Ridley is playable. By getting people riled up, speculating, arguing, and wondering about Ridley and his appearance, Sakurai is giving attention to Ridley. It's the Streisand effect at it's very finest and it's been known to work plenty of times before. It isn't a stretch by any means to say Sakurai is using the same method to promote a newcomer in the future.