User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-38501836-20190212124916/@comment-32573280-20190212173135

I don't think Elmenhilde will join Issei's Peerage.

Also all Highschool DxD EX did was confirm Elmenhilde joining Issei's harem not her joining his Peerage.