It's not just for new wikis. It's called the Google sandbox in the SEO world and it's something that had been around for years and affects every new domain. Ne

It's not just for new wikis. It's called the Google sandbox in the SEO world and it's something that had been around for years and affects every new domain. New domains need to prove they can be trusted to get out of the sandbox and external links from trusted sources are the best way to do that and shorten the time spent in the sandbox. Big wikis like this go online with thousands of pages on a brand new domain. Without any external trust signal it just looks like spam for Google