That's a great idea, force coach to play a formation he doesn't want to play, we should throw some bunga bunga party while we at it, and Allegri will feel like he is at Milan again.
How the board could have known, when even Allegri didn't know, we only changed formation because of injuries. Also let's not forget that Allegri arrived at the last minute, with less than a month before transfer window closed, and he needed to evaluate players he had at the disposal, and also many weren't there because they had prolonged vacation because of WC.
And please stop with possible hypothetical situations