I have a guess about how Mario Odyssey will be. What we see on the trailer are probably all the Hubs in the game, and I have some arguments to sustain this "theory", but please, don't take this too serious, after all it is just a guess 😀 So here we go!
When the trailer starts, we can see Mario jumping out from the swers of New Donk City and then starts walking, during the city scenes, we can see some strange shining doors that Mario can probably enter, due to the fact that it is THE SAME "shining style" that appears later on the trailer when Mario enters the Crazy Cap "store" on the Mexican village.
I believe that those Shining Doors are the stages of that Hub, because it wouldn't make any sense New Donk City being the only Hub, since Mario travels to diferent locations where we can see peaceful NPCs just like on the City, the only exception is the Cubism-like world. Not that this is some kind of law of the game, sure we can see some laser thing on the Mexican village, but my point is that all of the areas shown had peaceful NPCs right from the start of the Hub.
On New Donk City we can see 4 shining doors, if that remains like a pattern for all Hubs, the probably have AT LEAST 16 stages, which sounds great and pretty close to the Mario 64 number of stages.
Besides all this, I guess there will be some kind of "events" on the Hubs, like on Super Mario Sunshine, we will probably see this on Odyssey too. An Example is on the end of the trailer when Mario is fighting that HUGE enemy (maybe it is a boss) on the top of the city's tallest building, or even Mario fighting those tanks under a intense rain.
These are my guesses, I could talk about Mario wearing a lot of hats or being able to upgrade the hat but that is pretty obvious at this point, considering the enphasis on hats of this game, BUT HEY, ITS JUST A THEORY….
Thank you for reading and sorry for a bad grammar, English is not my native english 😀
Discussion started at here by Pina0509