It's a joke so over played it make's the Tashi Ceiling seem hip.
Go read Frankie's reply to Fyre today it should provide some insight. Fyre was talking about specific technical hurdles preventing TU changes from happening before the TU hit. One of the most memorable was the description of how Halo's map files work and how many things you see on a map are actually hardcoded into the map file.
Fyre was both right and wrong on some of his claims about the TU, and when folks were calling him out on his errors, the .map association was made because of how he constantly refereed to specific limitations of the .map files.
It was a joke, it's well played out, but like the Tashi Ceiling, it won't be going away any time soon from folk's memories.