So, since we're all over the place and ravenous, why not a crazy theory!
What if the character is Layton?
Now, hear me out, because you're going to have to suspend your disbelief as this only gets crazier.
They say it's a 1st-party newcomer, that didn't win the ballot, but is popular enough that they would be expected to eventually join the series. Roger also didn't specify that his info was Smash-related necessarily, nor did he ever say it was just one thing.
So, what if Nintendo bought Level-5 and Layton was now a 1st-party character that they've been working on for a while, and the 8-/9-10 hype scale announcement coming soon that Roger was talking about is both?
We've had the Layton VA rumor still not de confirmed to my knowledge, Nintendo may be publishing Yokai Watch in the West but they're advertising it like crazy, and Layton is one of the most adored characters in Europe, one that people constantly out in their fake leaks about region-based Ballot DLC because he's that hype a character at least over there, and popular here and in Japan obviously as well.
The whole "it will break the media" is Level-5 becoming part of Nintendo.
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Okay, so that's my crazy theory. I'm completely aware of how crazy it is, so don't attack me for having thought it up!