Wikipedia agrees with the activity history PyPI themselves posted in TFA and indicates the index at its original home under python.org went live in November 2002, and PEP 301 was posted with present-tense descriptions of the URL where the index was available on 11/8/2002. But,

AFAICS PEP 301 linked only to a demo site until April 2003:

https://github.com/python/peps/commit/c773b1b2ce0a2817