The INSTALL file included with the musicbrainz server contains instructions to fetch the wikidocs transclusion table from the following URL:

http://musicbrainz.org/static/wikidocs/index.txt

This works, however that file may be outdated if it is served from pingu. All wikidocs and wikidoc editing is redirected to astro, so that is where the musicbrainz server writes to that file, and that is where it should be served from.

(well, atleast I think it may be served from pingu, I don't see a specific rule for this file in the nginx config).