Evidence from March–April 2021 shows that U.S. vaccine eligibility restrictions based on narrow priority tiers did largely “fall by the wayside” within roughly six weeks of the late‑February 2021 recording, even though overall demand was still high.

1. Context at the time of the prediction (late February 2021)

   • Early in 2021, vaccine supply was limited and most states strictly prioritized high‑risk groups (health‑care workers, nursing homes, older adults), with many older adults still unable to get vaccinated because supply remained constrained. (kff.org) This is the “nonsensical” maze of prioritization Friedberg was referring to.

2. What happened over the next ~6 weeks

   • On March 11, 2021, President Biden directed all states to make all adults eligible for vaccination no later than May 1, a clear signal that the federal government expected rapidly increasing supply and a move away from narrow prioritization rules. (en.wikipedia.org)
   • By late March, a growing number of states had already opened eligibility to all adults 16+ (for example, Alaska on March 9, Mississippi on March 16, West Virginia on March 22, Utah on March 24, Georgia on March 25, and Arizona in late March). (kvia.com)
   • Around March 29–31 (about 5–6 weeks after Feb 20), many more states—including Texas, Oklahoma, Louisiana, Ohio, North Dakota, Kansas, Minnesota, and Indiana—either opened or were in the process of opening eligibility to anyone 16 and older, effectively discarding the earlier, finely tiered priority phases. (kvia.com)
   • Federal communications by March 29 and April 6 explicitly emphasized that confusing eligibility rules and restrictions were ending, with Biden announcing that 90% of U.S. adults would be eligible by April 19 and then formally moving the national target so that all adults would be eligible by April 19. (bidenwhitehouse.archives.gov) By April 19, all states had in fact made adults 16+ eligible, meaning the priority‑tier system had been effectively abandoned nationwide. (naag.org)

3. Did supply actually “outstrip” the old prioritization rules?

   • Analyses from KFF note that for the first months of rollout, demand greatly exceeded supply and that supply constraints plus restricted eligibility meant most people couldn’t be vaccinated even if they wanted to. (kff.org) They estimate that the point where overall national supply started to outpace willing demand came only in late April or early May 2021, slightly after Friedberg’s six‑week horizon. (kff.org)
   • However, states began dropping rigid tiered restrictions in late March and early April precisely because rapidly rising supply (more Pfizer/Moderna output plus the J&J authorization) made it feasible to open up to all adults, even if demand still exceeded supply overall. News coverage at the time explicitly tied the quick relaxation of eligibility rules to expectations of much larger incoming vaccine shipments. (medicalxpress.com)

4. Assessment

   • Timing: Within about six weeks of Feb 20 (i.e., by the very beginning of April), a substantial share of U.S. states had already opened vaccines to all adults or announced imminent dates to do so, and the federal government had clearly set in motion the end of the tight prioritization regime.
   • Substance: The core claim—that increasing vaccine supply would force many of the restrictive priority rules to be relaxed or dropped in that timeframe—matches what actually happened. The only nuance is that demand still exceeded supply nationally; the mechanism (“supply outstrips demand”) was a bit early if interpreted literally at the national level. But his practical prediction about the collapse of restrictive eligibility rules within about six weeks due to improving supply was essentially borne out.

Given that the key observable outcome (widespread relaxation/abandonment of prioritization rules in roughly the predicted window, driven by rising supply) did in fact occur, the prediction is best classified as right, with the caveat that the tipping point where supply fully exceeded demand came a few weeks later.