Theme is no longer on wordpress theme directory

Theme removal reasons are not revealed. They could range anywhere from the developer no longer wanting it available, to guideline violations, to security vulnerabilities.

If a theme is no longer available, that’s a good enough reason on its own to find a new one: https://www.ads-software.com/themes/browse/new/

Also, the theme you’re referring to is still in the directory: https://www.ads-software.com/themes/contango/

It’s no longer in search results because it hasn’t been updated since 2015, another good reason to find a new theme: https://www.ads-software.com/themes/browse/new/