User blog comment:B214/Season 3 confirmed!!!!!!/@comment-1359322-20141212134202/@comment-24502975-20141212142127

It wouldn't make sense to add Rias/Akeno/Gasper/Koneko in v9:

For one thing, it's a second-year trip. They can't get around that. Secondly, there's not enough Hero-Faction members to deal with them all 1v1 (and it would be unfair to leave them fighting Leonardo's monsters).