Muscles require nutrients to exist, and without it they atrophy. So being more muscular means you need additional calories to stay muscular. Whenever I stop working out for a while, I usually stop force feeding myself too, and my muscles disappear pretty rapidly. If I continue eating a ton then the muscles stick around longer, but I also get fatter, since I’m not burning the excess.
The point I was trying to make is that even if it doesn’t increase your metabolism, it increases your minimum caloric need. So, you can eat more without getting fat, or you can lose fat without eating less. It’s not even “can”, you must eat more to meet your kcal minimum. That’s well documented scientifically as well. So ultimately the effect is the same, it’s easier to lose fat when you have more muscles.