That was a stage, not a character. IStages were and still are completely expected to be revealed on a common daily pic day. It was actual characters that were not being revealed except during roster additions. It's not whether or not stage hazards are a big deal, but that actual characters most certainly are big deals, playable or not.
The thing is, Ridley could still be a stage hazard and that particular element not be revealed until Sakurai decides so. If you wanna believe Ridley should have already been revealed by now if he was a part of the stage, that's fine. That's not what I believe. This pokemon reveal to me only makes the contrary plausible in my eyes. If Ridley is revealed on a common day, I won't be as surprised now.
The way I see things is that if Ridley's a stage hazard, then he's just that. I don't see why he should be revealed as such in a trailer or in any big way. Doesn't matter what he is outside of Smash Bros, Sakurai can throw in recognition like that with a little comment, if he's a stage hazard in Smash Bros then he's nothing more than that. Not even Toad got a daily picture dedicated to him, he was just included in the big Peach gallery, so presuming he isn't a playable character he didn't even get a little comment or nod from Sakurai, he's just there. It's not about the character, but about the role of the character, and if the character isn't playable, then there's no reason to make a big thing out of it.
If Ridley's a stage hazard, I always expected him to be revealed in a standard pic of the day with Sakurai throwing in a little comment like "Sometimes Ridley gets out of hiding and assaults the Pyrosphere. Look out Luigi!" because there's no reason to make a bigger deal out of it. Even in the Brawl Dojo's Boss update Ridley was treaten like any other boss, on par with Petey Piranha and Rayquaza. Again, in this game's case it's not the character that matters, but the role of the character. At least that's how I've seen things being handled.
