Summary: The Docker images for Dart being published under https://hub.docker.com/r/google/dart are being discontinued after 31st December 2021.
What can break: After 31st December 2021 we will stop publishing new SDK releases under https://hub.docker.com/r/google/dart, and these will thus go stale and no longer track new releases.
Mitigation: Use the new Docker published under https://hub.docker.com/_/dart. These are are Docker Official Images, and have been structured to have better size and performance than the older images.
Freeback: Feedback on this can be posted in the tracking issue: