US Airways Dividend miles, which is merging to American Airlines AAdvantage program sometime in early 2015, has changed its off-peak award chart effective immediately.
EDIT: Seems that the off-peak to South America became non available on US Airways metal per discontinuance of the Charlotte to Sao Paulo route starting on October 1st (see here) and Rio de Janeiro gone already, although CLT-GIG is back for December-January (see here).
US Airways has been offering off-peak awards to number of destinations in the past during the lower demand periods at reduced number of miles.
You can access US Airways Dividend Miles award chart here.
Now, the airline has effective immediately removed the off-peak awards between North America or Hawaii and South America.
Conclusion
This is probably the “new” way that the combined American Airlines and US Airways inform their frequent flier members about award chart changes. American Airlines discontinued the Oneworld awards (read more here) without any prior notice earlier this year.