I could see them doing one every event that ties in. Actually I could see them doing a few during CT because they could say that Santa hid presents or something.Unlikely. They did this for "national scavenger hunt day" which was a good excuse for them to do another scavenger hunt.
I do think they'll have more scavenger hunts as the egg and now spoon seemed fairly successful; but I don't think it'll be done again soon like the Easter eggs. Maybe they'll do one in July with a prize of priority seating for summer nights shows and maybe HoS/ChristmasTown