Forum Moderators: Robert Charlton & goodroi
"Offer a site map to your users with links that point to the important parts of your site. If the site map is larger than 100 or so links, you may want to break the site map into separate pages."
I read it as a recommendation to limit the number of links on a page to 100 links. Even though a sitemap is usually internal links, I'd expect it to go for external links as well. It is possible that Google added the 100 links limit for human usability reasons.