OK, here is how it works.
1) Alcohol cannot be placed in the room, as it must be signed-for by an adult.
2) SSR does not have in-room dining for someone to deliver food.
3) ONLY the Front Desk Runner delivers to the rooms.
4) You can send something to be delivered AFTER they check-in.
5) No specific time is guaranteed for delivery, as the Runner has other duties.
6) Besides, they would be held up since they don't know the guest's check-in time.
NOTE: Whether by Disney Florist or outside companies, people are not permitted to enter the room for deliveries of flowers/baskets/etc. All room deliveries, except luggage, go through the Front Desk. Plus, DVC resorts (like SSR and OKW) now do "room ready" assigning at the Front Desk, so in many cases, the room is not even assigned until the guest walks up to the Front Desk.
NOTE2: With the exception of Club Floors at Deluxe resorts, they do not put flowers/basket/etc into the rooms prior to check-in (and frequently, not even on the Club Floor). There are too many reasons that particular room may not be the one the guest will get: . . . mechanical failure . . . room not clean . . . someone else wanted that room so they were swapped.