By David Shepardson (Reuters) – General Motors Co on Tuesday said it will not mandate workers return to offices before 2023 after it had told them on Friday that they would be expected to work three days on-campus each week later this year. The U.S. automaker told employees who have been working remotely that it does “not plan to mandate which days of the week will be collaboration days. In no scenario will our Work Appropriately evolution begin before Q1 2023.” GM on Friday had cited the dramatic improvement in the COVID landscape for the change “to drive the best collaboration, enterprise mi…