Southwest Airlines is currently in a rolling_out status with a high fleet coverage ratio of 86.2%, which generally implies near-guaranteed Starlink availability on most routes. However, perplexity-verified context indicates that as of May 2026, no aircraft are yet equipped, and there are zero confirmed observations or community sightings on the ONT->HOU route. Given the rollout is announced to begin in summer 2026 and no recent news or sightings confirm active deployment, the probability is anchored conservatively at 0.30, reflecting the fleet coverage floor for rolling_out airlines with high fleet ratios but no direct evidence on this route yet.