With the way KEP is shaping up, the Rocket Hideout can easily stay with little issue. I don't expect it to be a problem at all. Therefore, in the interest of keeping Lavender Tower's progression the same, it's being restored. I do expect some Lavender Tower floors to be nommed, though.
I expect Silph to also be salvageable but I also really hate Silph.
Oh, also, the Game Corner guard has been buffed. He sucks. They call that a guard??
Underwater Tunnel is a new area that links Route 25 to Route 10, basically just being a straight tunnel needing Surf to traverse.
Also given Seafoam Islands and Lorelei's room an unused palette that gives it a more icy feel