But 63000 at 1 minute each could be 26 weeks (at 40 hours per week.) Even with committes divided by school or program, no way. Note the full article says they meet over a few weeks. Not months.
Remember, most kids won’t be true finalists. It could be that piles of apps that rate low (and all readers agreed,) are grouped. And so on. Anyone on committee would have access to review notes (very short, btw,) and only rare cases of those discussed. Adcoms like efficiency.
In committee, the real contenders (where all reviewers already agreed,) might get reviewed for geo/sub geo or other diversity/balance, then rubber stamped. Borderline, especially where there were no clear cut better contenders (or where prior readers disagreed,) would get discussion. Still quick.