Only one step away from connection from SP list to Planner.
Now Planner has an option to export to Excel.
Imagine all the possibilities that you could have with the import function.

One of them: EXport from a SP list to Excel, then import this excel list to planner for reporting and follow up.

This intermediate step might cover the gap between SP task list and Planneruntil there is an interface between task lists in SP and Planner