Oh wow. Almost ten weeks of silence, and then we get three videos in one day. It's a start, at least.
Of the three, I consider the first half of the first one more interesting. It shows that Alola has got some changes to some areas. Most have been mentioned already, but in addition, it looks like it is now possible to surf a little along Poni Breaker Coast, outside of the Ruins of Hope. There also seems to be some rocks or something in the sea between Ula'ula Island and Aether Paradise.
As for the second trailer, for Kommo-O, it seems like they really want to push the "shiny new toy" effect onto Kommo-O. A move that boosts all stats and is strong enough to OHKO fellow pseudo-legendaries. They might as well have put subtitles in: "Kommo-O is the best now, folks! Forget about Salamence and Garchomp, look how weak they are! Kommo-O is the new best thing! It can knock out two opponents and make itself stronger afterwards!". I haven't seen such a blatant example of this since Jurassic Park 3. Or the two Mega Charizard, I guess, only that was a case of a fan-favourite being granted a lot of power so it would be popular again. This time, they hope to create fans of their Shiny New Pseudo-Legendary by granting power first.
Worst of all, if this works as intended, and Kommo-O becomes an unstoppable beast because of it: How are they going to prevent Kommo-O and Clamorous Soulblaze from sweeping VGC year after year? The obvious answer seems to be the most cynical one: In Gen 8, Z-moves will be banned, just as conveniently as Mega Stones were banned in Gen VII, so a new Shiny New Toy can enter the stage.
And lastly, the Game Informer video. I take it that this feature won't exactly take Smogon by storm. It is probably no coincidence that all the trainers seen in that video (with one exception?) were girl characters. However, I think it is interesting how much this feature focuses on the 3D models and their animations. Fitting accessories onto the models (which presumably move as the models do), freezing them mid-animation to show all the poses... this is clearly Game Freak getting some good mileage out of all the time and money it must have taken to create models and animations for all Pokémon last generation. It must have been expensive to create that package, but the possibilities it opens up for seem vast. Related to this, the animation for Kommo-O's Z-move is pretty darn impressive too.