Well, Spring Break is here and summer is coming so they want guests to take uninterrupted views of the castle. Remember how cranes ruins the their castle pics and some even just edits it out.What's plan with the pace/scheduling of these decorations? It seems like they have a team of two people who go up each night and put up a single decoration then call it a night? Wouldn't it make more sense to not do anything at this point, and then closer to the 50th put it all up over the course of a single week with a larger team? The current method seems like an inefficient time use for all the machinery involved, and the fact that the moat needs to be drained for the length of the construction.
Perhaps they wanted to test a few molded pieces first and see how they looked before ordering or installing the remainder? It can't simply be a money savings technique.