Hi David!
Thank you for bringing your question to the Disney Parks Moms Panel!
I have actually seen the same announcement about
Captain Jack Sparrow's Pirate Tutorial, and if you look at the showtimes on the official Walt Disney World website, there are none listed after September 29, 2018. I am really sorry that the timing has not worked out for your trip and for your pirate-loving son. I would definitely still ask a Cast Member upon arrival if there are any showtimes for that day. Things are constantly changing, and it's possible that the show will extend longer than currently scheduled.
I think you will all love
Mickey's Not-So-Scary Halloween Party. Since you have a pirate fan, be sure to check out the special addition to the Pirates of the Caribbean attraction. During the party, you can join some rookie pirates in their search for "Gunpowder Pete."
I hope this helps! Please let me know if you have any other questions.