rigel

On 3/21/16, issued a one-way AA Award ticket PVG-DFW-JFK under old chart in F, travel date is late Dec. 2016

In Oct. 2016, received a voice mail from AA saying due to aircraft change, F is not available and needs me to call to discuss alternatives;

In late Dec. 2016, 1 day prior to the scheduled travel date, I called AA, brought up the voice mail thing and request to make a change. The agent was gonna charge me per the new award chart but I insist it's not my problem and require the change to make a change of routing and date, with the same O and D. After the 20 mins call, with nothing to cost, the following ticket is issued: PVG-NRT-ORD-JFK, travel date: 3/19/17. On my AA accounts, it says "Ticketed 12/29/2016"

My question: Since the ticketed date is "12/29/2016", which is not 3/21/2016 anymore, if I keep the exact routing and class, is it possible that I change the flight to a later date beyond 3/21/2017 without any other surcharges in miles?