Retainers in Disguise

[Tsukino]

And yeah, at the bottom it says that sometime in the future they'd like to update it so you can take them into dungeons.

Not only that, but in the stream they basically said they need to work out how to balance the AI to handle dungeon mechanics. It could end up being just another dead end they mentioned once and then never actually follow up on because it ends up being too difficult to actually implement.