Can confirm this is still functional. You can look at the files that TimeMachine will be ignoring by using sudo mdfind "com_apple_backup_excludeItem = 'com.apple.backupd'", which I found via http://apple.stackexchange.com/a/25833/35333.
Comparing a “before” and “after” on my machine, I found that /Users/justinn/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux was introduced when selecting the checkbox.