Again, the point isn't that they use swords. The point is that the devs said the reason they went Awakening/Fates only was for the sake of variety, and then went and added two repeat characters. They should've said "we're only added characters from Waifu Emblem because they make us more money" (or the PR version of it) instead of treating their fanbase like fucking idiots. Then again it seems many people bought their lame excuse so hey, good for them.
And the point I'm trying to make is that there is no "two repeat characters", since male Corrin and female Robin are simple skins. I don't think the "too many Swords" is a good excuse for the SD/Awakening/Fates focus and I would like characters from other games in the series, but let's not spread misinformation here.
About the trailer, I'm guessing we'll see a similar Fates trailer and then the Shadow Dragon reveals. Wonder if they left the Shadow Dragon side until last because Awakening/Fates may gather more interest or because the Shadow Dragon side will be, in a way, the one with the least "safe" choices and thus the most "surprising" for lack of a better word?