are you sure? I say the sun will rise tomorrow even though it hasn't yet happened.
First, a fact is something that can be verified. There is evidence the sun is almost certain to come up tomorrow, but it is not yet verifiable fact.
Second, although it is not proven what will happen tomorrow, science will tell you the sun has risen every day the earth and sun have existed, and there are thousands of years of writings, hieroglyphs and cave drawings to evidence the history of the sun rising. There is no history of Williams bulking up and becoming successful in the NFL to judge from.
All that said, I actually agree that with some additional bulk and strength Williams has a very good chance to become a quality player. It just isn't fact yet.