that's basically what I said, I think the only thing we need is date and length at most
I don't think this should affect their announcement of Xenoblade DLC though, informed people will make their purchase decision based on if they think it's worth or not(which we wouldn't know until next fall I guess)
I think a really cool idea instead of having a trailer or set-up would be if they patched the game little by little, and you can find some DLC related influence with regard to Champion's Ballad, only IF you have the season pass purchased or maybe if you already beat Ganon(This might be seen as kind of a douchey move because it's in game advertisement that teases you for a DLC)
I think that would be more interesting than a trailer, since there are so many players playing and the internet, even if they add something pretty obscure chances are that people will find it and share it
Which then people can piece together towards the release of the DLC