It doesn't matter if it is irrelevant in the end, speculators could legitamtely cite this as a reason that she might not be included. Objectively.
...And how can today's pic of the day objectively de-confirm Palutena from any angle?
Because if we look at objective facts:
R.O.B appeared as a statue on the Port Town Aero Dive stage in Brawl, yet still made it into the playable roster, as already mentioned. To expand on this fact, the reason why he appeared as a statue on that stage in the first place is because on the original Port Town Aero Dive track in F-Zero GX, that same R.O.B statue is in the same spot. Because the entire Brawl stage is a recreation of the original track.
While I can't speak for this myself, Kid Icarus players can recognise that location, or can list off locations in the Kid Icarus universe that contain statues of Palutena. So based on the facts of the R.O.B statue in Brawl, and using the same logic, we can ascertain that Palutena's statue would be included on this stage regardless of whether or not she is playable, for the sole purpose of universe authenticity.
And as last Friday's picture showed us, the development team is perfectly willing to make a character be a stage NPC and playable in the same game, even if it requires modelling and animating a stand-in. While the Spirit Tracks Link isn't technically the same character as playable Toon Link, who is the Wind Waker incarnation, it would confuse players if they aren't clued in on the Zelda franchise, because they look so similar. However, the appearance of an inanimate statue would not confuse players, because it's just that. So they would not need to make a new model to replace the Palutena statue. And again, based on the R.O.B statue's existance in Brawl, there is objectively no reason for us to believe a character can't be featured in the background while also being playable.
This screenshot cannot be used as an objective piece of evidence towards her being playable OR non-playable. It is merely a screenshot that confirms that we have a Kid Icarus stage on the Wii U version, and said stage just so happens to have a statue of Palutena. The statue was most likely put there to give people an idea of where this place actually is in the Kid Icarus universe.
Now, personally, I think Sakurai is teasing us, because releasing this shot a week after those leaked images is a very convenient coincidence. However, that's not objective evidence in favour of her playable likelihood either. It's just a bit funny.