As of November 30, 2025, it’s too early to judge this prediction, because the forecast window is 3–4 years from 2025, i.e., roughly until late 2028–late 2029.

On the factual side:

• Yamanaka-factor / partial cellular reprogramming is still largely in preclinical and early clinical stages; longevity commentators note that only the first induced-pluripotent-stem-cell (iPSC)–derived therapies have just reached tightly regulated clinical trials and that progress toward rejuvenation therapies is slow. (fightaging.org)
• There is active medical tourism for advanced stem-cell and iPSC-related treatments, especially in places like Japan, marketed for anti‑aging and regenerative purposes, but these are mostly mesenchymal stem cell therapies and targeted iPSC applications (retina, Parkinson’s, etc.), not open Yamanaka-factor-style rejuvenation protein/gene therapies sold to general consumers. (placidway.com)

So, by late 2025, the specific scenario Chamath described — medical tourists flying to a lightly regulated jurisdiction (e.g., Costa Rica or similar) to receive Yamanaka-factor-style rejuvenation protein therapies outside U.S. clinical‑trial channels — has not clearly materialized yet, but the deadline for his forecast is still several years away. We therefore can’t say the prediction is right or wrong at this point, only that it remains open.