Important nitpick: this wasn't reported to the "Debian maintainers". In DEBIAN this was fixed long ago. The problem persists and was reported to people that work with Docker images, which is primarily people that don't want to use Debian the normal way, and don't benefit from many of the Debian niceties.

The summary of what they did on the page is largely accurate. I mean, the repository on GitHub that cooks the official Docker Debian images is indeed primarily maintained by a Debian maintainer who is a member of many different Debian teams, even if it is not an official artifact of Debian. And the problem is fixed in Docker, too, but it sounds like the issue is that they'd like the old Docker images with the backdoored packages to be removed.

And sure, you definitely lose some niceties of Debian when you run it under Docker. You also lose some niceties of Docker when you don't.