Same exact thing happened to me with Delta and SXM. Booked award flights and one month prior to travel, Delta canceled all flights to SXM and canceled the route. Wouldn't rebook us with other carriers because it was an award flight even though it was accommodating paying customers with flights with other carriers.

We had to scramble to get down there so we wouldn't lose our non-refundable expensive hotel accommodations.

Delta ended up restarting service shortly thereafter. Seems to be a typical cycle for them.