We have updated our Copy Plan experience – please try it out today!
This improvement includes the ability to choose an existing group or team to copy the plan into (or choose to create a new group). You’ll also be able to customize what gets copied over. Attachments can only be copied over into existing groups/teams.
You can get more details here – https://techcommunity.microsoft.com/t5/planner-blog/expanding-the-copy-plan-and-filtering-features-based-on-your/ba-p/1483491
An error occurred while saving the commentSue Webb commented
It's crazy that this still isn't possible in October 2019.