Okay since I can't find the original image I'll just use this one.
Anyway, honestly how hard would it be to just photoshop a lock onto that, to mess with us and make us think there's more characters? Like others have stated Sakurai has never shown locked items, they just kinda appear as little surprises.
What if just to mess with us and cause further chaos, the leaker (who has lied in the past) just put a lock on the menu and called it a day? Does it make any sense that Sakurai's only means of showing a mode is locked would be a small lock in the top left of the screen?
On top of that the top right of the lock is chipped, seems kinda odd and out of place. Of all the things we've questioned the photoshop of, this should be the most glaring one.
As much as I want there to still be characters this is just a glaring discrepancy that seems off to me.