The returning content is nice to see and new content was more than I expected. Adding following pokemon to the overworld makes sense since Amity Square was probably just limited by the times.
Turtwig gets Leafage now.
EDIT: Also it shows PS instead of HP in this one clip for some reason, probably from another language.
It mentioned a software update was required when showing the Union Room.
It feels weird to have the wifi battles have the background be the actual Union Room, though I guess I'm comparing it to the original static background and the modern green grid rooms. The Galactic battle background looks pretty good too, so I hope they let you pick and choose possibly.
Another learnset change showing this isn't just a faithful remake, Roserade gets Leaf Tornado. It doesn't even learn this in the main games!
EDIT: I made a post after this already but I'll put some more thoughts down here.
They changed the wild encounter text from "Wild MON appeared" to "A wild MON appeared", but now it's very different. Not sure how I feel about this one. The trainer text is pretty much the same as modern times though, down to the static pose slide-in.
Fashion is a good addition even though most of the time it's on chibis.
I like how seals have been expanded for the new 3D environment. Speaking of seals, they also showed Sunshine Cherrim being sent out directly but I'm not going to read too much into that.
Overall I think they've made some good additions and I was nicely surprised. More potential variety is nice and they've confirmed a lot of mons here.