Thanks for this request. We are rolling out the links to planner boards for groups in Outlook desktop from the group card, so that should help get to the planner task list.
This request seems to be asking for the Outlook desktop tasks list to also show planner tasks. Can you help us understand the use cases and details on the actions you expect to perform with planner tasks in Outlook?
Thanks.Martin Samuelsson commented
We need to have tasks in one single place, not multiple.
Please consider leveraging Microsoft To-Do https://todo.microsoft.com/en-us