This did not come as a surprise, because Paint 3D never reached anywhere close to the popularity of its classic brother, the original Paint app that is still used by plenty of people to quickly create and edit their photos and images.
Microsoft, at that time, said:
“3D Viewer and Paint 3D will no longer be preinstalled on clean installs of the latest Insider Preview builds. Both apps will still be available in the Store and will stay on your device after an OS update. So, if you upgraded your PC like normal, you shouldn’t see these apps changed in your app list.”
Getting rid of the Paint 3D app is still possible, but even if you remove it from the OS, the context menu entry that is supposed to let you edit your photos is still there.
If you have uninstalled Paint 3D, and right-click and image and click the “Edit with Paint 3D” option, Windows 10 automatically points you to the Microsoft Store to install the application.
But as discovered, the latest Windows 10 preview build removes the context menu entry when Paint 3D is gone. The change should go live for all devices running the operating system by the time the next feature update strolls around.
There is also a chance that the next feature update also becomes the first one to no longer install Paint 3D automatically, though Microsoft could wait for the fall update to make this change.
In any case, we should find out in April or May, when Windows 10 21H1 lands.