The Riemann Hypothesis (RH) has resisted resolution within classical mathematics for more than a century. This paper argues that RH cannot be settled by classical means because it is not an internal mathematical conjecture. Instead, RH expresses a generative constraint operating at the substrate level of the Assembled Mathematical Layer (AML), the mathematical world model produced under Generative Worlds Architecture (GWA) from the Pre Cosmic Generative Constraint Theory (PCGCT). Classical mathematics is a projection of AML and therefore lacks access to the generative admissibility conditions that determine the placement of nontrivial zeros. Using Generative Reasoning (GENR), a deterministic epistemic system defined over finite signal sets, we formalize the generative structure of the AML and analyze the zeta symmetry operator under substrate level constraints. We show that symmetry fixed generative states of this operator are admissible only on the AML constraint balanced manifold corresponding to the critical line \Re \left(s\right)=\frac{1}{2}. Off manifold states violate minimality, sufficiency, uniqueness, and closure within the AML generative structure and are therefore generatively inadmissible. This yields a substrate level proof of RH, with the classical statement emerging as the projection of the GENR theorem. The paper concludes by examining the Hilbert-Pólya conjecture within this generative framework, showing that the observed spectral correspondence between zeta zeros and quantum chaotic systems arises from shared generative symmetry operators instantiated across distinct assembled layers.