That would be my best guess. Maybe this will be the FE Switch game that was announced? I really want an original title, but I'll take this too.
As for other rumors, I'm just hearing the usual suspects (Smash Switch, Mario X Rabbids, Beyond Good & Evil 2)
Pokemon Stars on Switch has some compelling signs in the wild. Nintendo pulled the previous Direct from Youtube, which could indicate that they wanted to avoid confusion when they announce the new one (they only ever do this before announcing a new version of an already released Pokemon game). Also, the Official Direct page on Nintendo's website has changed to have an open spot, which happens when a new Direct is imminent.
We should start an E3 Prediction Pool.