What's got me leery about this exposition is how the end of the first arc didn't just hint at unfinished business with Mizuchi's death, but Satori herself said Miko was going to "make a move" regarding the string of possessions. Miko's first appearance having her covered in shadow suggests a dark motive, and as we know she is every bit an opportunist.
It's possible she's spinning a yarn of nonsense to throw off the investigation because, imo, this new spirit's MO doesn't fit how Mizuchi did her thing; this one seems MUCH more openly aggressive against bystanders. If the newbie is just rampaging against youkai, then a hermit would have an incentive to support her.
I'm hoping that when Satori wakes she's going drop a real truth nuke that will turn this on its head. It's bizarre to give her a fresh new outfit just for her to be a jobber of no consequence. There's too much setup for it to be something random like Miko magically intuiting it's another Mizuchi.
Then again, it is ZUN.
