If they decide to use Blender to create the 3D art, you might look into Godot's escn format. Last I recall, someone had built tools in the Editor for somehow having Blender export a scene as a specialized format that could be directly opened in Godot (an exported scene, i.e. *.escn format). More info can be found here and there is plenty of other documentation for importing 3D assets in the official docs.
Have fun!