There is a vacuum left by Exhentai, now, and some place will inevitably fill it, whether it's a mirror of the original or some other site. Not everything can be recovered, but as long as there's demand and a place willing to host it, the content will continue to be published.

But hopefully the admin will reconsider and give somebody else the keys to keep the original operation running. It sucks to lose so much just because one person couldn't carry on.