Soups can be healthy for weight loss as long as the soups you eat don't contain a lot of calories.
When eating soup for weight loss you should choose soups such as tomato soup or other broth based soups which are lower in calories.
Potato soup is okay for weight loss too but it contains more calories than tomato or broth based soups do.
So as long as you choose soups that contain low calories then the soups are healthy and can help with weight loss.