I’ve just watched the teaser again and I think this-
Zelda falling away at beginning
Link on Island with looks like Washa Bluff below him
Rocks falling away from Hyrule Castle and maybe becoming an Island.
I then went on and watched the next two trailers, one for the first BotW and one about the making.
Apparently they used the Japanese Jomon period for BotW. And the image that comes up in BotW.2 is similar to the objects below-
View attachment 47568View attachment 47569View attachment 47570
Just my thoughts and may well be BS, but we will have to wait & see!