The sound clips actually might be for the Wii U game modes. The 3DS can be used as a Wii U controller for Smash 4, so those sounds might play from the 3DS when playing one of those game modes. Either that, or they were planned features that were cut - 8-player Smash sounds awesome, until you recall that Ice Climbers were cut because the 3DS couldn't handle 4 of them at a time (It also better explains DHD's extra reticle colors). We can rule out planned future DLC for 3DS for this reason.
So... how do we take this? If they are indeed Wii U sound effects, we have two mode confirmations that were safe guesses, and a huge blow to the big game mode... They don't exactly counter each other out, in favor of debunking the leak. One could argue that Tower of Smash
is "Event Match," and I think that chance is the only thread this is hanging on right now. However, if they were cut features, then they're all meaningless to the leak.
If the leak isn't real, or even just Ridley/Mewtwo not being on the Wii U before the 3DS version, I really won't know what to think of Sakurai. Well, I'd a know a few things, all of which censored and moddable on the forums, but just in his train of thought. Ridley/Mewtwo would generate massive hype and make fans happy so not including them on the roster really does make little sense to me other than Sakurai just not wanting to do the most requested things the fans want, and instead putting in a lot of his own creations/franchises.
This bothers me more than anything else. Those two characters have been strongly hinted at in previous trailers (along with Metalface, Dark Pit, and Mr. Game and Watch, the latter two having made it in but also being the only two characters we saw in full detail without a hard confirmation). Metalface is most likely a boss, but the fact that Ridley was also teased with a shadow concerns me as it does make it seem more likely that Ridley is a boss... Lastly - and most frustratingly - there have been analyses of Greninja's trailer that indicate the Pokemon we saw at first wasn't Greninja, and more closely resembled Mewtwo all the way up until it started using Water Shuriken. The suggestion of Mewtwo's appearance was not an accident.
Why? Why would Sakurai do this if they weren't playable? No matter how you slice it,
Nintendo is a company that makes money, and teasing your customers with something they're not going to get is a
terrible business decision. The facts we do have don't make any sense.