Explanation:

The transfers associated with multi-step routes were created in the following order using PULL rules:

3-step deliveries:

1. Delivery Order (OUT)
2. Packing Operation (PACK)
3. Picking (PICK)

2-step deliveries:

1. Delivery Order (OUT)
2. Picking (PICK)

Even though transfers are created in one order (ship, pack, pick), they are processed in the reverse order (pick, pack, then ship). To minimize the number of transfers created in advance and increase flexibility, transfers are now being created as follows:

1. Pick
2. Pack (when using a 3-step delivery process)
3. Ship

The next transfer is created after the previous transfer is validated. Odoo uses a push action instead of a pull action. 

Example:

 I'll use a three-step route to show the workflow.  I create a sales order and confirm it. Notice only one transfer is made; it's the pick. 

After I validate the pick, the pack is created. There are two transfers now. The delivery order will be created after I validate the transfer.

Create a test database at https://www.odoo.com/trial to test this new behavior!