I think it depends on the TYPE of yoga you are doing. There are a lot of different styles that vary from more static stretches and poses to constant movements. Are you doing a more static style of yoga, or a flow-style of yoga (such as Vinyasa). I do not believe yoga should be your ONLY form of exercise, but it is a great supplement.
When practiced consistently and correctly, all styles of yoga improve the mind-body connection. This can help you be more conscious of your body's needs and listening to your body. Improving that mind body connection can help you better navigate your diet, as you make more mindful choices when eating. Personally, I LOVE supplementing my weight loss with a vinyasa yoga that focuses on strength building. But I also jog, bike, and do some strength training the more "traditional" way.
Best of luck!
I tried to add a URL for more information on yoga styles and weight loss, but I haven't posed enough
If you search google for "yoga for weight loss", the Live Science article is what I was trying to add.