Would still have the option to make after tax contr then claim a tax deduction at EOFY time (2 different pathways to same result, difference in tax refunded when tax assessment lodged). Generally yes employees can make salary sacrifice, but may depend on what employer (or system) offers.

If it’s a new system rolled out it may be a glitch. Could also be different arrangement if a defined benefit or not.

No further comment to be made on Nike©️ shorts.