I think that the challenge for a trailer is going to be the balance between the text on it and the visual. Considering how many people arrived because of the youtube video of the jutsu demo that's a must for sure, maybe keeping the aesthics of the videos released after that, trying to make a video with the jutsus on the night and maybe against mobs or a world boss would make it easier to do it in game and it would feel more like a player experience.
The map is one of the big things of the game so showing how big it is would be smart so people get excited over the fact that they have a lot to explore.
Maybe it would be good to give a teaser of how byakugan and sharingan is going to be, probably show a little bit of sarutobi monkey so is not left behind. The originality of the cosmetics, the other masteries like medic and swordsman so people know what to expect in game even if they want more stuff.
In general, on this one I feel like the best way to hype the people and bring more attention to the server would be to make people feel the gameplay of the game instead of visuals like cinematics (to be honest it might be too early to do this).
Maybe more than a trailer it would be good to have a video with the summary of every little clip posted with a little more on each one and an update on the jutsus. One youtube video with this could be good enough for people to learn more about the game in a single place and also mention the release on may so people ask less that.