As an SE, this year to date I have attempted to upgrade seven intercontinental flights at +/- the seven day window. Of those seven, two cleared immediately (and those were to/from NRT post-Tsunami when J was very empty). Four cleared at the gate and one remains pending this Saturday, but I expect it too will clear at the gate.

Bottom line - my experience is that AC tends to zero out R space before the seven day window unless the J cabin has tons of availability, so re-read Andrew's post. I'll be willing to bet there are a good number of SE's waitlisted for your flight.