First off ACP-PLV, the printing company where the alleged leaker works and took the snapchat from, recently deleted a marketing video from it's official Youtube channel that showed off their work and production environment. This came immediately after people started matching the settings on
this paper in the leak to materials and printing devices used by that company as shown in the video. That video was previously a pretty big marketing tool for them, and the current theory is that the only reason they could have to delete it would be that it could now be used to compromise sensitive information; i.e. confirming that the Grinch leak was real.
Second, in a
recent interview Sakurai stated that the reason for delaying the last Nintendo Direct was that because of the earthquake, they "could no longer use the original draft [they] had prepared." At the time, a lot of people speculated that they were originally going to announce Isaac, but cut his part out of the direct because he would have shown off earthquake-based moves which would be disrespectful. Someone just dug up this screenshot from a 4chan thread, supposedly screencapped from the official site directly after the Direct with what looks like a hasty, poorly done photoshop on Olimar and Little Mac.
This just so happens to be the exact spot that Isaac appears in the leaked banner.
This would seem to point to the fact that they originally intended to reveal Isaac and Isabelle together, but had to hastily cut him out of the Direct and the official artwork following the earthquake.
