Shy Guys are a main enemy and character in Mario games, going back to Super Mario Bros. 2 and Tetris Attack. While the main enemy in Yoshi games (i.e. Yoshi's Island, Yoshi's Story, Yoshi's Wooly World, etc) and a reoccuring character in Mario spin-offs, for too long Shy Guys of all kinds have been shoved to the side. Pushed down and viewed as the equivilent of a Goomba for Yoshi games. Though there are some occasional displays of their due respect. In several Mario sports game spin-offs they're playable, most recently in Mario Tennis Aces.
However, there seems to be a positive change in the Paper Mario: The Origami King trailer. There are several keys that indicate that The Origami King is giving Shy Guys their proper respect. Speaking of which, near the beginning of the trailer we're shown The Origami King transforming into himself from his disguise as a Shy Guy. You may think that this means nothing but au contraire they could have chosen any enemy. They chose a Shy Guy despite all odds. This is more likely to symbollically represent the true power that any plain Shy Guy has.
The trailer does not want you to confuse its very clear message about Shy Guys either. As we see a Shy Guy in one of Bowser Jr.'s Clown Cars, swooping down from the heavens to rescue Mario. Besides from being a biblical reference, this also shows how easily Shy Guy could of changed fate. They could of let the main character die or they could of saved it, which Shy Guy did because they are good.
The most important and influential moment of the trailer was the few seconds where we got the most important reveal: a whole Shy Guy city. Well technically, the inhabitants are Snifits, a variant of the Shy Guy that shoots projectiles, with a mask that looks more like a gas mask than their typical hockey mask.
The fact that there is so many details that shows how valued all Shy Guys are in the 2020's upcoming best seller, Paper Mario: The Origami King.