Any tracking event is required - not just on lodgement.   Although the following is about sending an item, not a return, I am sure it will apply.

If you use a tracked postage service, reliably upload valid tracking and use an eBay-integrated carrier for your eBay orders:

• Your listings will be eligible for shorter Estimated Delivery Dates which will improve listing conversion
• After the item has been sent, if there is at least one valid tracking event, we’ll protect you by:
  • Resolving any ‘Item not received’ requests