You can "docker push" any binary image to index.docker.io.
However if you don't use a Dockerfile, you won't be able to use the Trusted Build feature, and other users won't be ae to verify which source the image was built from. So your image will remain a second-class cotizen.
However if you don't use a Dockerfile, you won't be able to use the Trusted Build feature, and other users won't be ae to verify which source the image was built from. So your image will remain a second-class cotizen.