After Leif posts GotM21 we will have completed the first cycle of civs. The question to the customers is should we start in on the new civs, or is it too soon to expect the majority of players to be ready for DLC
That is a bit harder to implement in VI vs V there are checks that can be done in the V saves that we don't have the capabilities to do in VII think we shall add restrictions(e.g. no player declaration of war / have at least 3 level 3 spies at winning, etc.) to make things more interesting.
But perhaps the best compromise would be to alternate which of the two games each month uses a DLC civ? That way there will always be at least one game that everyone can play.