State Government included an active transport component (aka a bike link) in the SW Metro Project, originally called the East West Pedestrian and Cycling Link. Recently it has been renamed the South West Active Transport Link, which does sound a little better!
SWATL will provide a bike route along the railway corridor from Campsie to Bankstown.
Preliminary work to identify the exact route is scheduled in 2025, with construction in 2026 after the Metro is opened.
Bicycle NSW and our IWBC coordinator John McNeil have been on a ride along the likely route and arent impressed so far with the parts going through town centres, like Campsie. Also a few big intersections have to be negotiated. Cycle paths between town centres in or along the railway corridor might be much better, more space to build a good facility.

Bicycle NSW facebook link :