i think @ice.d has a good point though that it is cumbersome to have to update twice when docker_manager needs an update. You have to first to update docker_manager and then wait for that to complete and then update Discourse (or Update all) to update Discourse and any plugins.
Updating docker_manager takes long enough that I often will start that update and then go away to do something else, and then I only remember later to return to update Discourse.
It would be a nice touch if the UI still allowed the Update all button in this case, and just update docker_manager first and then automatically proceed to update Discourse. If the docker_manager update fails, the process could be interrupted.