Do we have a constructor hiding in our midst? It seem the NY Times crosswords themes are a few weeks behind our active threads..

Today it was a collection of Tom Swifts-- just last month we had an active thread of them..
and its not the first time-- words i have stumbled across here, or themes, have re-appeared a few weeks later in puzzles-- has any one else noticed this?-- or is just one of those things.. like the D-Day cross word puzzle?