It would be bad. He's not a seasoned enough ring worker yet, nor does he have the proven promo cutting ability to carry segments. That would be fine, except for the aforementioned lack of ring work. Brock could work a whole match fantastically and Ryback can't do that. He is a one-trick pony who does 3 minute squashes.
They will have to find a way to have a great match with him and get a DQ finish at the end. It's the only way to keep him from looking like a joke and make sure the belt drop isn't a failure.