From another comment below, it's just a nice short title to convey that we're going back in time and not one to set your watch by.
We first submitted the article to the CACM a while ago.
The review process takes some time and "Twelve years of
Docker containers" didn't have quite the same vibe.
(The CACM reviewers helped improve our article quite a bit. The time spent there was worth it!)
Makes sense! Thanks for working on it -- truly a wonderful paper!