So they wave the fare difference in the case of one of the flight you are flying get cancelled if that isn't the case the only wave the fee for reboking.
I am wrong I just checked the document and it says that yeah they shouldn't collect the fare diffrence
After making an actual dummy booking. My first statement is indeed correct. As the flight is still operational. I am not entitled to a change of destination or even a free change. Just trying to rebook the same route couple of months later would involve a 400 USD change on a 1700 USD ticket. ARN-BKK