He wants XF to submit a DMCA to try and take the site down.
That site is using Cloudflare, so you have to submit a DMCA to CF who forwards it to the provider, who may not take it seriously and if they're not located in the US they don't have to listen to a DMCA anyway. @ByDost - it's best you just ignore the site and let XF do what they can with the reports you've already sent.
Remember XenForo is not an all powerful entity in which it can demand a site take down a pirated XenForo install. Plus for all you know the site could very well be be licensed.