Can't say the Kirby stage will be saved for a Wii U discussion because we don't even have a 3DS Kirby stage yet, so where's the logic in that?
I also don't think Meta Knight necessarily deconfirms him either. I mean, since he's already been confirmed it makes for a bigger chance for Dedede to have a more prominent role in the hypothetical trailer.
Originally I had considered Meta Knight would be shown with him similar to the Greninja/Charizard reveal, but if that were the case, wouldn't have only revealed Meta Knight first and not Dedede instead? (I mean, Dedede is more relevant after all.)
But from the looks of it, we'll be getting a Robin/Lucina trailer. Unknown if we'll get a veteran or not with him, but based on Captain Falcon's appearance, it proves that characters don't always need to be relevant to get announced together. With that being said, what veteran do you think would get announced with Bandana Dee since there's none left from Kirby?
One more thing, King Dedede's Final Smash could be an issue, but I think Sakurai would want to use Masked Dedede instead when given the chance, I mean, look at Giga Mac. I don't think he's an Assist Trophy, since Bandana Dee is more important than Knuckle Joe is. The only thing left is Stage Hazard, but I doubt it considering we have Whispy Woods, Kracko, etc.
I would have at least thought we would see a Bandana Dee Assist Trophy by now if he is one. (We haven't seen one for Issac either. Or Barbara the Bat.)
We still have the hint of the Green Greens remix. And did anyone else notice how the Melee Fire Emblem theme was in Robin and Lucina's trailer? Green Greens is also from Melee, so maybe there's that?