No doubt their Staff prepare the brief, but the Royal who is doing the visit must read it, question it, understand a fair bit about the organisation to be visited
You'd hope so, yes, but let's not forget the confirmation bias at play here
Those prepared to host such a visit tend to be pretty "pro" in the first place, and you only have to witness the gasps of admiration over the royal's slightest squeak or gribbet to appreciate that the cries of "Ooooo they knew so much" perhaps aren't entirely objective