Microsoft has long announced that its Office applications will support Macs with Apple processors. Shortly after Apple presented new Macs with M1 chips, the Redmond company released beta versions of Office applications supporting these new machines for its testers registered in "Insider Fast".
The released applications are universal versions, running on Macs with Intel processors as well as new M1 chips (and A12 development computers, which Apple lends to registered developers for a fee of about $500).
The release date for the final versions of Office for Macs with M1 chip support is unknown.
You can subscribe to Microsoft's beta test program here.