Here's another thing I'm unsure about. LATAM finally sent me emails about my cancelled and moved up (but actually later also cancelled) SCL-IPC November flights. But when I click the link in the email and then click on the Outbound flights button on the page it draws, they say:

"There are no flights available for this date. You can return later, you have until December 31, 2021 to reschedule your trip."

Do I have until Dec 31 to book a new flight, through the end of the schedule at that time, even though Dec 31 is more than a month after my original flight?

Or do I have to book a flight by November that flies before Dec 31?

I'm not clear on which they mean, and that's a big difference.

In case it matters, the significance of Dec 31 might be that I booked the original ticket on Dec 31 2020.

If I book a date in 2022 that later again cancelled, will they allow me to change again?