Currently have award flights from LAX-HND, return NRT-LAX for late October that I'm considering cancelling. (The Japan covid thread isn't particularly inspiring in terms of planning a Japan trip at the moment.) If I do so, I'm trying to determine when the miles may expire. The miles were initially transferred from Amex in December 2019 for a trip in 2020 that was cancelled due to covid. I subsequently booked a 2021 trip that was also covid cancelled. I can't find a record of the expiration, but I *think* that in both cases, ANA changed the mileage expiration to three years from the cancellation--meaning sometime in 2024. Does that sound right? If that's correct, can I assume that if I then cancel this award, the miles will have the 2024 cancellation date?

Neither of my flights (NH125/NH6) were part of the recent cancellation--I suppose that still could happen, but I'm not counting on that.