A publicly timestamped prediction dated May 9, 2025 described specific, non‑GR gravitational‑wave damping behaviors expected from the Spacetime Viscosity and Centrifugal Force (SVCF) framework. These predictions included accelerated post‑merger decay, suppressed recoil, reduced ringdown, nonlinear amplitude damping, and minimal remnant formation. At the time of prediction, only the preliminary LIGO/Virgo alert for event S250331o existed; no parameter estimation, ringdown analysis, recoil reconstruction, or template mismatch data had been released. Subsequent detailed data releases for S250331o confirmed every predicted feature: HasRemnant = 0.0, suppressed ringdown, nonlinear amplitude tapering, absence of recoil, and deviations from GR templates. This paper documents the original timestamped prediction, compares it to later observational data, and demonstrates that SVCF viscosity provides a consistent physical mechanism for the observed damping. The prediction was publicly posted and timestamped prior to the availability of the confirming data, establishing a falsifiable and independently verifiable forecast. This constitutes the first documented pre‑event prediction of viscous gravitational‑wave damping and provides empirical support for the SVCF framework and the Rheoviscion substrate.