User blog comment:B214/The i don't want to answer anymore FAQ center/@comment-86.153.129.0-20160818145102/@comment-1359322-20160818153936

I already link the official website above, you can check it out. Either way this anime will air in 2017 earliest, so we should expect the chances of DxD getting a 4th season in 2017 is very slim now.