While there may be some who reject Pharmacy offer in favour of something else, leaving some spots available for the late round, I wouldn't rely on that. In any case, there won't be too many spots up for grabs.
But if you are looking at DFEE places, most of those people who have received offer for both CSP and DFEE pharmacy will reject DFEE places, and thus probably leaving quite a number of places vacant. You may consider that option if pharmacy is your passion and if you are eligible for FEE-HELP program, which enables you to borrow up to $80,000 from the government towards DFEE cost. However since there are only about 30 DFEE places to begin with, can't tell exactly how many places will become vacant and available.
While we don't know yet the UAI component of this year's cut-off (along with 150/200 in STAT), judging from the collapse in cut-off of CSU Pharmacy at Orange and Wagga Wagga, I suspect that UAI for Sydney Pharmacy went down a bit as well. If your UAI is close to previous years' cut-off (i.e. 95~96), you should have a shot. You should keep in mind, however that "high-demand" courses whose UAI went down in the main round may have their UAI bouncing back and shooting up in the late round as many people who are disappointed with main-round offer change direction into another discipline that are appealing to them.
Hope that helps you make your decision. I advice you to consult USYD Pharmacy faculty and check what I said are accurate before you take them into considration.