I thought you were talking about the idea he was cleaning the servers from such content, but now I see you were actually saying he completely pulled the plug.

So yes, that is a posibility, but not giving any sort of heads up its closing or anything is just weird even if that were the case, this would not constitute a larger admission than what he already did since he already had said he was defederating from an instance to avoid that kind of content. And to my knowledge, as long as they are moderating this stuff social media and the like dont put the owner in trouble, otherwise every ceo of twitter or facebook would have gone to prison a long time ago.