Maybe empty packages do not actually exist physically and it’s just Unreal way of saying something got broken, as the following code lists no assets, though presumably empty package should be in this folder.
import unreal
folder = "/Game/NewFolder1/test"
assets = unreal.EditorAssetLibrary.list_assets(folder, recursive=True, include_folder=True)
# No output.
for asset_path in assets:
print(asset_path)
print('---')