yes i have done this and yes they told me the same thing. It is because you don't get your room number until you check in so they don't know where to have them delivered until you check in and get that room number.
But really it isn't that much of a problem, they will deliver them then and you still get your flowers. I feel as long as i get the flowers it is ok that they aren't sitting there the moment I walk in the door. I will take them anytime.
Marylee