There is no standard that requires these fall-restraint devices to be attached to the racks, but...
Design codes ask for safety bars to be fixed to the beams (front and back) because they can move from side to side. There is no clear recommendation in the codes for wire mesh decking. We know that although waterfall type wire mesh will not laterally move and cannot simply fall off the rack, it is better to attach them to beams as they sometimes get lifted by pallets during operation.
To learn more on wire mesh: https://www.damotech.com/blog/storage-rack-safety-an-inseparable-pair-rack-tunnels-and-wire-mesh-decking