If Delta doesn't free up additional availability, then even Diamonds could be in for the BF on some flights. I'll be very happy to be proven wrong, but I have some flights booked that are V0 or X0 at ten days out. If that holds, noone will be upgraded at the 6 (or 5/3/1) day window.
This is why I don't think DM will be a big factor. With so many flights these days being V/X=0 until DoD I am not certain yet how DM will impact UG success.