My guess, is that its a LOT of security fixes.
All things considered, I doubt it. This has probably been planned for a long time, they probably barely know about the leaks yet, and even if they did, they don't have time to figure out how people got the data. This is probably something else they've had planned for some time already.
I could be wrong, but I highly doubt they can have that quick of a turnover rate on this kind of thing.
I think we can all agree that the 2-repped Starfox, DK and Metroid franchises need a new character in Smash.
But if only one could be added as DLC, which series would you like to get the upgrade & why?
DK hands down, no questions asked. 5th best selling real Nintendo franchise, 6th if you count the fad Mii games from the Wii generation. Massive popularity and sales dating back to the SNES games. The Donkey Kong games were pretty good as well and is what brought Nintendo into the limelight, but DKC is the real start of the DK IP. And Returns revived DKC to a total of 6m in one single game, with the 3DS remake/port receiving 1.68m, which in of itself means that the port even sold more than the saviors of the Fire Emblem and Kid Icarus IP's. And Returns alone sold more than the entire Metroid Prime Trilogy.
Future DKC and DK games will likely gradually bring back the rest of the DKC characters and animal buddies, and DK has quite the extended cast.