Yes, they do. Though it isn't very hard to crush or crumble a bouillon cube or two. An Italian friend of mine made very good, very simple zucchini. She'd slice them VERY thin, and mince a few cloves of garlic. Then she'd sauté it all quickly in olive oil. Over high heat so the zucchini wouldn't get soggy. And she'd sprinkle them with a crumbled bouillon cube to add more flavor.
Very simple, but tasty. One of the few ways I like zucchini, which I usually find boring. Have to be careful about salt, because of course the cube is salty.