Two things. first, I don't know why everyone says that Nintendo doesn't put out paid DLC, they do it all the time. to name a few off the top of my head: FE awakening, New Super Mario bros 2, And PMD Gates to infinity. I think you may be referring to the fact that they usually tease a bit of free DLC if you bought the game at a certain time, but I doubt it because FE Awakening did so as well.
Second, I'm all for trusting this certain leak, but lets refer to all leaks as just what they usually are. I for one still think that the Sal leak is bull**** for several reasons I'd rather not get into an argument on here. So for everyone's sake, even if Falco is conformed, lets not get TOO hype.