My kids go with the flow and don't give a whit if they didn't get to help plan anything when we take a trip...they are happy and grateful to be going on a trip. They don't care where we go or what we do or if they had time to help plan (honestly, since I am paying, I don't really ask their opinion anyway....)
We told them 15 minutes before the limo arrived to take us to the airport and they have begged us to do it again, and we did one trip where we pinned up a wall map of the USA and gave them a clue to a city or landmark every day so they could plot out the path and eventually figured out we were headed toward Florida. Once they figured that out, we gave them a clue each day as to what we were going to be doing in Florida (WDW was only part of the 10 day trip).
My kids don't get hung up on what they need to pack, who needs to know, what they planned on doing that weekend, or anything else for that matter. They trust that if I have planned something, I have taken care of the details, and they know DH and I well enough that we will pick things to do, places to eat, and all of that based on what we know the kids would like. I know that DS2 would pick blue for his magic band, DS1 would pick yellow, DD would pick green. I know that DS2 cannot eat seafood (even though he *wants* to love it like his siblings...LOL, he just cannot force himself to like it!) I know that DD would LOVE AK, and the boys would have more fun at DHS. We know our kids well and we plan accordingly.
IDK...we went through a few years when we couldn't give our kids ANYTHING, and they were happy with what we did have. Although those years were hard, it taught my kids to accept what they are given and not worry about what they don't have. So, I laugh when I hear about kids having to wrap their minds around going to WDW and needing time to process it (special needs aside). We didn't raise our kids to be so tightly wound. We are too often spontaneous....they wouldn't last long in our house if they couldn't go with the flow!
Bottom line....you gotta know your kids.
Mine are (almost) 15, (almost) 11, and 9