That response about being reviewed by the committee is probably not the end of the world. It might mean he hasn't gotten any applications yet, hasn't had time to look at any/yours, yours might be in the hands of someone else, etc. Maybe you're his #2 and he's waiting to gauge interest from his #1. Maybe he's waiting to hear about fellowships/grant funding. None of those are reasons that he would want to explain via email, but aren't necessarily terrible.
Or maybe he already threw your application in the trash haha. When you are admitted into the lab, as opposed to the program as a whole, there are a lot more variables that go into it. It also extends the time things take to shake themselves out with funding and spots being taken by others. All you can really do is try not to stress and hang on for the ride. :mrgreen: