Sometimes the QF res agents will let you know, or maybe just something along the lines of "you should be ok" or "you don't stand a chance". I am assuming you are waitlisted for a full J fare and the cabin is currently sold out. You could get some idea of possibilitiy by looking at the F availability. Some of the J pax may be waitlisted for upgrades into Z and that can free some J about 3 days out.

Another thing to check (but might be hard to find now) the seatmap to see if it is a Skybed config. If it is, then there are only 50 J seats and that could mean a long waitlist for a Sunday QF11. Sundays are always busy with people getting to the US for the beginning of the work week.

If you mean you are waitlisted for an upgrade into business class (U) then you might see some movement on Friday. But note my comment above regarding Sunday flights to the USA.