Lands absolutely are great for what they used to be. History and nostalgia, the very thing Disney's brand thrives on, are what keeps things close to people's hearts. When I think of Tomorrowland, I think of the PeopleMover, the Rocket Rods, the old Astro Orbiter, Radio Disney, Asimo, etc etc.. People hold an attachment to those things and that's what makes imagineers reconsider all their options before demolishing any land. They want to do their best to improve instead of restarting, not to mention it's cost effective which is probably priority number 1.
As for Frozen, well........ I'm sure that announcement will come some day, but it's pretty much six feet under.
They can do anything with the space to spruce it up on a whim. Glow Fest, ElecTRONica, Mad Tea Party were all hits. When the state opens and the park goes back to 100% capacity, they'll definitely want to throw some type of party to celebrate that magic. And Hollywoodland will be waiting...