No, it does not. OGL 1.0(a) is not irrevocable and does not include the legal language that makes it irrevocable under the law as it has evolved since its original creation. It includes language that can be interpreted to mean it can be deauthorized, which in effect revokes the license. And this is exactly how WOTC is interpreting that language. These flaws are precisely why the current situation is even possible. Finally, OGL 1.0(a) is written and copyrighted by WOTC. A truly open license would be maintained and enforced by an independent 3rd party, usually a non-profit or law firm. This is how Creative Commons works, and how the proposed ORC license will work.