My idea of a standalone Dante trailer would be a sequel for the Sephiroth trailer, featuring Galeem & Dharkon both getting destroyed in one strike, before zooming in to Dante on his motorcycle with his ****-eating grin while this plays.
Then it goes to gameplay footage and goes back to CGI cutscene constantly.
Nice idea, if it were to happen! Here's my deep take on it, though:
I don't this can canonically work, unless canon-related issues are actually being ignored by the trailer development team.
Sephiroth's trailer seems to be taking place after you rescue all the fighters in WoL. You can tell because Dark Realm characters like Richter and Sonic are in it, while Bayonetta is one of the last characters you can rescue. I think the trailer takes place as half of the roster goes after Galeem (and her eventually getting sliced in two by Sephiroth), which could possibly mean the other's after Dharkon.
So in light of Dante, maybe a good Dante trailer being canon could be him slicing Dharkon in two or something after saving another half of the Smash roster, i.e. Luigi, Simon, Pac-man, Steve, etc.