On the Conceptual Origin of the H0 Tension, Universal Deceleration, and the Non-universality of Cosmological Estimators

The so-called H₀ tension — the persistent discrepancy between local distance ladder measurements (H₀ ≈ 73 km/s/Mpc) and CMB-derived values (H₀ ≈ 67 km/s/Mpc) — has been conventionally interpreted as an anomaly requiring new physics or undiscovered systematic errors. This technical note argues that this interpretation rests on an undemonstrated assumption: that a single universal value of H₀ must be recovered by all measurement procedures. Building on the MRUV cosmological framework established in Prevedello (2025a, 2025b), where the universal deceleration parameter Φ ≈ 5.57 × 10⁻¹⁰ m/s² replaces dark matter and dark energy as the fundamental physical invariant, we demonstrate that H₀ is not a universal constant but a procedure-dependent estimator: Ĥ = Ĥ(Π, D), where Π denotes the inference pipeline and D the physical domain. Under conditions of operational non-equivalence between pipelines — formally established in Propositions A.1 and A.2 — the persistence of ΔH₀ is a methodological inevitability, not a measurement failure. The kinematic crossing at z ≈ 0.38, confirmed independently by cosmic chronometers with 0.007σ agreement without parameter adjustment, provides an empirical bridge between frameworks. The recent TDCOSMO 2025 result (H₀ = 71.6 +3.9/−3.3 km/s/Mpc), intermediate between CMB and local ladder values, is interpreted as direct evidence of this estimator non-universality. Four testable predictions with explicit falsification criteria are presented.