Lol I mean it's possible. However Mystic did literally say "nope" when I asked if they or any of their sources had seen the real banner.
Let me get back to this (later in this post).
Here's the thing...
I sincerely doubt there's a banner v.1.0. They likely didn't get their marketing art people on the banner idea until the roster was finalized-- I don't mean finalized as in the roster plan, I mean the point in development when you know exactly how many characters you're going to ship at launch and who they are. Because actually drawing the banner would not take that much time once the idea was decided upon, and they would need to run the concept through multiple people in the bureaucratic ladder-- possibly even Sakurai-- before it was okayed as the promotional idea.
I very much doubt there was ever an early banner that was seen by anybody but the people who made it. Then, as the release strategy was finalized, they worked backwards from their banner's final form, with each character as a separate layer over top of the blank Battlefield backdrop, to make other banners to coincide with each announcement.
I just can't see a scenario where someone low enough on the food chain to want to leak this info would see a final banner that needed updated.
I'm aware of how the banner was constructed, sometimes you have to say something potentially incorrect to work your way to the truth.
Anyway, second idea.
What about preliminary sketches for the banner?
They would have to be made, right? As an artist myself you don't just
draw images of that quality right onto the canvas, you have to do rough sketches.
What if Sakurai made the roster plan, and then either he
(Sakurai can draw) or someone else drew some concepts and preliminary sketches while they waited for confirmation that they could use certain characters (I'm 99.9˙% certain this is not illegal).
Obviously, some of the characters in this roster plan would be denied for whatever reason, and be scrapped, but sketches of how (and maybe where) they would be posed on the banner would still exist in storage (Nintendo does not just destroy concept art, all those early sketches of Capsule Monsters and early Pocket Monsters that Game Freak showed earlier proves this;
Yes, I'm aware Game Freak and Nintendo aren't the same thing, Miyamoto still has the concept art for Super Mario Bros. on Graph Paper).
This would allow for sources and insiders to have "seen" something, but
(getting back to Akiak's post) not have seen the completed mural. If they had seen gameplay footage, I'd have thought that footage would have leaked by now, right?