From the text posted, it looks like you can status match every year.

At the end of this year, cardholder's status in this program will return to its existing level unless cardholder ... b) resubmits proof of status on another airline, per the process described below.

It looks like you should be good if you can get plat on another airline. Also, AA tends to match through 2/28 the following year if you match before June/July, and through the year after if you do it after. I don't recall the exact date.