The latest on dockerhub is still 1.98.0 and there is no 1.98.1 tag despite a 1.98.1 release.
Are the 1/1-* tags not updated to the latest stable? Or is 1.98.1 not considered the latest stable? rustup seems to think so and so do I. Or is this just a bug?
The "official" presumably means that it's Docker's official Rust image, not the Rust team's official Docker image. It's maintained under Docker's github.
It's both the Rust team's official image and Docker's official image. All Docker hub official images are published through Docker's own CI system, so there's a delay as new releases work their way through that.