Got it, thanks.
But what about if there's a change of class within 1 year? So let's say I make a booking on 3/18/16 for 2/1/17 at current rates in F. On 4/25/16, I change the booking to 3/16/17. If F is available, looks like I'll be able to keep the existing award rate. But what if F isn't available, only J. At that point, will I get those J seats at the current rate, or the rate as of 3/22/16?