Ok folks, when deciding on a course of action and you think something bad might happen, look into the abyss! What's the worst think the could go wrong? In this case, the worst result of some early prep work is that the new boss mightn't like it and decide to do it differently, resulting in some wasted work (and some disappointed workers). All up, that's not such a bad risk to be balanced against the rewards of getting some early organisation in and not leaving everything to the last moment. So, if you think you can cope with the possibility of a bit of disappointment, dive in and go for it!
(Having said all that, I'm not in a position to do anything so I will now slink away with my tail between my legs... )