If Parting/Sharp Remark does function like a U-Turn type move that lowers stats, that would have huge tactical possibilities. It could let a team-mate set up easily, let a partner overcome a counter that would normally beat it or continually force switches by pivoting between two users.
I really hope that's what it does.
EDIT: So it's confirmed to work just like that, while lowering Attack and Special attack. That move is going to be so useful.