Update to delivery section of positioning slide

Why is this change being made? Updating the process flow to reflect the new reality of the PS Delivery Efficiency plan.

There has been much discussion in Slack and in the PS Leaders call and in the weekly PMO call regarding these now agreed upon changes to the process. -->

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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