-The two very different themes will remain
-The Blade will be removed
-The area of which Ripsaw and The Blade were will be become a night, and possible day, entertainment area. With a permanent outdoor stage with entertainment every night for hotel guests.
-Galactica and Nemesis will be open till late along with the roller coaster restaurant.
-Possibly see a new restaurant open too, perhaps slightly cheaper, could always expand out of the park onto to the car park.
-Sub Terra will re open.
I always thought Forbidden Valley by itself would be a great stand-alone part of the park. In fact, I made Forbidden Valley as a standalone park in Planet Coaster:https://www.youtube.com/watch?v=sucfyoOKYpw
The only problem, is that inevitably you would get people who jump a barrier to stay in Alton Towers overnight, because there are no barbed-wire fences etc that prevent people from moving from Forbidden Valley to the Gardens or Gloomy Wood.
It would be a good idea though, maybe every Friday Night FV is open later than usual, till 9 or something. I can't imagine the residents would be happy hearing people's Nemesis screams until dusk.