In the meantime, one feature from the new app has been backported: To Do integration.
The new Outlook for Windows that Microsoft is still testing also has a dedicated To Do button.
At least for the moment, older Outlook tasks will live alongside the To Do page.
Microsoft
There’s no word on when, or if, To Do integration will arrive in Outlook for Mac.
There is astandalone To Do app for macOS, though.
Source:Microsoft Blog,Microsoft Support