We've done this for the kids. Many times over the years for different reasons - calls for their birthdays, calls before a trip to Disney world. The kids have always enjoyed it. (These were the character calls thru the Disney Movie Rewards program - not sure if that's even still around)
I scheduled a call the day after we booked the cruise and I have another call scheduled for the night before we leave. Goofy called and just chatted about how excited he was to hear we were going on a cruise. I don't remember exactly what he said, but it was cute, specific to cruising, and very quick. Mickey is calling before we leave for our cruise. The 3 year old enjoyed it and wanted him to call again. The older three thought it was cute - added to the excitement.