No, there hasn't been a Tropical Fruit Ice Cream Festival at Unbelievable Acres going back about 10 years. The Palm Beach Chapter of the Rare Fruit Council still holds the annual event for their members and guests at Mount's Botanical Garden in West Palm Beach.
BTW, I heard Gene on the radio this morning (South Florida Garden Show, Sundays, 7 - 9 am, 880 AM) saying that all of his Lychee trees are in bloom and his Longans are starting to bloom as well.
For more information about Gene Joyner's garden that he started in 1970:
www.unbelievableacresbotanicgardens.org