Dude, it's Animal Crossing. How can you make a substantial reveal trailer about it?
Isabelle is cleaning up the office, then a duck hunt duck flies through the office and scatters papers. She sighs, and picks them up. Right after she does so, the duck flies in again, this time being chased by the dog. She's more visibly annoyed, but she picks up the bigger mess they made. But then the duck flies through again followed by the dog and this time villager is following them shooting slingshot pebbles, making an even bigger mess.
Isabelle flips, grabs her pot ready to throw it, and then boom, title card says Isabelle turns over a new leaf. Heck, this one even gives her personality by having turn over a new leaf imply she's done with villager's stupid shit and is taking matters into her own hands.
OR, if we want to keep her pacifist and tease animal crossing as well with in-game assets, have it start out with isabelle at the bus station saying how the mayor never came back. Kapp'n appears with his same bus as the smash assist trophy, so she gets on and there's text hovering over about how it's her job to find them and bring them back, by force if she has to… then the video shifts from the in-game assets to cgi, with isabelle getting off the bus into new donk city, where she spots mario and villager fighting. She pulls out her fishing rod, aims at villager to catch him, and as she throws the line the title card appears, the Kapp'n remix starts playing, and BAM, gameplay.
I just came up with these two on the spot. It's really not that hard. Sure, they would have been more expensive and time-consuming to make, but that's a different problem. Coming up to the ideas is really not that hard, and if you have a 30 min brainstorming session with a couple actual artists I'm sure more ideas would appear.
Villager was just a sideshow for Megaman back in 2014.
More accurately, Villager was a sideshow to Smash 4 getting revealed. Much like Inklings were a sideshow to Smash Ultimate getting revealed. That Villager had jack-shit done for his trailer is not a reflection of animal crossing being difficult to cross-adapt with other games, it's just a reflection of the fact that the first characters revealed for the games get less dedicated trailers since the focus is the entirety of the game.
AND EVEN THEN when I think back I remember people watching the beginning of that trailer being jebaited into thinking it was animal crossing, until villager runs away and the letter has the smash logo, and then boom, logos and characters and then villager reappears netting mario and having killer eyes. To compare this treatment to the snorefest of isabelle's trailer is an injustice to how seamlessly they went from hyping up animal crossing to hyping up smash to hyping up the new character in smash.