User blog comment:GooerGaming/High School DxD BorN episode 8 review/@comment-97.103.233.248-20150525171758/@comment-26322543-20150525193308

The interview will happen after the RG. It was said in episode 7.

Azazel said they'd record a song in episode 6, and since a few days passed between 6 and 8, it's very possible Use went to record, since it took less than an afternoon to do it in the LN.