figlesquidge:
I wouldn't support metagaming in the same way I wouldn't support going CD. If the British leader declares a need for a sitter Spring 1901, fortunately finding one in his immediate family, that would be very amusing indeed. If whoever is playing Russia goes CD in 1917, at which point Germany takes Warsaw and Livonia, until Germany realized that he must to go on vacation soon, and would thus go CD by 1919, agreed to cede Ruhr, leave Belgium, and stop building fleets and armies, I would think that was very interesting.
Of course the game is based on the ideas, and not the details. That doesn't make it less interesting when the game contains events and themes that reflect historical fact. It shows how realistic the game is, and how human historical figures are.