When the sites that informed various well regarded answers on the sites get their due, their search engine rank rises. With such a well ranked site now pointing towards them, they rise in the results, often higher than the SO answer referencing it.
As a secondary issue, there's a relatively common black-hat-seo practice of buying a well regarded domain, and soaking that links for all they're worth to promote something. Their switch-flipping may have run afoul of systems designed to mitigate that.
When the sites that informed various well regarded answers on the sites get their due, their search engine rank rises. With such a well ranked site now pointing towards them, they rise in the results, often higher than the SO answer referencing it.
As a secondary issue, there's a relatively common black-hat-seo practice of buying a well regarded domain, and soaking that links for all they're worth to promote something. Their switch-flipping may have run afoul of systems designed to mitigate that.