We are going in Oct and was not able to get a FP for it. I emailed Disney and this is their response.
Thank you for contacting the Walt Disney World® Resort.
We're looking forward to seeing you!
My apologies. Maelstrom will not be open during your visit. I hope you will enjoy our other boat rides at Epcot®, Living With The Land and the Gran Fiesta Tour Starring The Three Caballeros.
If you have questions or need further assistance, feel free to contact us.