Whilst getting both Boss Ridley and Playable Ridley is a possible outcome, it makes me wonder what's the point in having a lava hazard on top as well (assuming it is, considering lava's missing in Pyrosphere FD). Having a boss hazard and lava hazard seems a bit much for a stage, especially since stages with Boss Characters as Stage Hazards, like Dr. Wily's stage (Yellow Devil, you can fight and defeat it) and Find Mii stage (Dark Emperor, you might be able to fight and defeat it), seem to only have 1 hazard each. Other stages with Boss characters have them causing the hazards, like Gerudo Valley's Twinrova and Mushroom Kingdom U's Kamek, without them the stages would be plain. Twinrova seems to cause fires (possibly icing up the place as well), and make the bridge collapse. Meanwhile with Kamek, he changes the scenery of the stage, so one example is that he changes the stage from the grass world to the seaworld (or whatever it is) and makes those Urchin creatures (spiked purple things) pop up from below. There are possibly other elements from New Super Mario Bros. U that haven't been mentioned or shown yet for that stage.
Note that, from what we've seen so far, the boss characters that are the hazards (that you can fight/may be able to fight) appear on stages when there's no platforms visible, but boss characters that cause hazards appear regardless of whether there's platforms or not. From the screenshots that we've seen so far in pictures, the platforms on Pyrosphere don't seem to have moved, so do they actually move or are they fixed? If they don't move, Ridley might clip through them, which isn't good for a boss to do. With proper bosses in past games (Master Hand, Crazy Hand, bosses in Sub Space Emissary), they've been on flat stages with no platforms. So having Ridley being the only boss to appear on a stage with platforms (that don't move for the fight), seems a bit odd and inconsistent. It also makes me think why turn off the lava and lava spores, and change those purple things for Pyrosphere FD, if they're just there to make the place look pretty and have little/no purpose, whilst "Boss-ly" is the only hazard for it.
Without Sakurai explaining the Pyrosphere stage and its Final Destination counterpart in full, we're still left in the dark. And the longer he keeps this going, the worse the conflict and tensions will be between the two sides. Announcing Ridley as a boss hazard and the lava is just nothing (at a big event), despite evidence of it being removed in the FD version, after all this time, would just be... well... awful... I know I seem to be like repeating things, but it just annoys me that if Sakurai chose Boss-ly as the hazard, that he has kept it all this time from us. Rather than telling us and letting us down quick and easy, like with de-confirmed characters, he ends up humiliating us at a big event. Yes, promoting a new mechanic's all fine and good, but don't wait so long to reveal something that will easily let fans down and get disappointed with, but at the same time allow haters of that character to ridicule the supporters for getting their hope up. Hopefully at E3, he'll state Ridley's playable, and the lava is the actual stage hazard.
Seriously, how can you hype up a character with a boss hazard role, so much when you know that the character's fans want that character as playable... ._.