It was a long time for Microsoft to realize that not only Windows should be the focus, but the apps. Today, most of the Microsoft-apps are available on all devices, not caring if they run on Windows, Android or macOS/iOS.
One of the best mobile apps I have experienced so far was Wunderlist which was later aquired by Microsoft. It also took a very long time to get used to the "new" Wunderlist entitled "To-Do". Microsoft To-Do seemed to be quite unfinished for a real long time but has definitely advanced and grown over time. Thanks to a Desktop version in Windows, sync between your favourite devices wasn't a problem either. Alas, a little scar was left - the missing macOS-version although To-Do made its way to iOS a long time ago.
This seems to be over now - Mac users already had the chance to pre-order the Desktop version. Now, the first users were notified that the pre-order of To-Do on macOS is available now.
When checking the AppStore, a search for To-Do already revealed an app by Microsoft. Not having participated in the pre-order-process before I still had the chance to enroll myself for the program.
Although I wasn't able to download the app directly, the AppStore shows that, approximately, Microsoft To-Do for macOS is scheduled for a release on tomorrow's June 17th, 2019. As long as you are running at least macOS 10.13 and a 64-Bit-CPU, To-Do may hit your machine tomorrow!
Edit: As the date switched to June 17th, the app was available and got instantly downloaded via the AppStore. Have fun!