I am not sure how AA rewards work but we do travel mostly to Aruba on reward points. See if you can put the points back into your account, most likely there will be a charge but it is better than loosing the points.
We got two of our sons point tickets to Aruba for this Xmas but once we saw potential exam schedule these flights wouldn't work. We had to pay $90 each to put the points back into account but we got all the taxes we paid for the flight refunded. For our rewards program there is no high/low season, but they have certain amount of seats designated at different reward levels. The closer you get to departing, generally, the higher the reward points it will cost you.
Last year when I went to Aruba in March, we were able to find flights for my cousin to join me in Aruba at the lower reward rate close to travel. Just a fluke but we had to do an extra stop to make it happen.
Anyway, this doesn't really help you with AA but check about getting those points back into your account. Let us know what happens.