The last I heard, the issue is that the person that maintained the code left, so it's still on some super old version of PHP. So they need to upgrade the entire codebase to a modern version, which can be a very involved process. I could definitely be wrong though.
I want 4chan to live to see another day so I can keep getting these greentexts. I’m thinking that they must be in some serious trouble if the site is still down…