The announced Civilization 5 December patch will change quite a lot of gameplay elements and it will invalidate some old answers on this site.
The changes will render some answers factually incorrect, an example is the question about buying courthouses or the question about research overflow.
Should we edit the answers to those questions immediately with a note on the behaviour after the upcoming patch? Or should we wait until it is officially released?
Should the old, incorrect answer remain (side-by-side with an updated answer) after the patch is released or should we consistently remove any outdated information? In this case it is a Steam game where almost everyone is playing the latest patch automatically, but with offline mode it is still possible to play older versions. Removing the outdated part would tidy up the question and the old answer is still available in the revision history.