With the merge of Wastelands and the burnt biome, there's a void that needs filling.
And that's where me and my idea come in.
For the burnt biome's replacement, I suggest adding a swamp/bayou. A triecious wilderness dotted with fishing huts, moonshine distilleries that house the various special types of buff drinks as loot, as well as a possible plantation house/mansion.
Alongside those locations, a new animal in the form of Gators could be added, adding onto the stakes of visiting the biome, as well as possibly opening up room for a boss gator. Perhaps protecting a certain Elixir?
Then finally, this could finally lay the groundwork for a new vehicle, hovercrafts. Able to ride over water, circumventing the problems boats have had in the past within the game.