It's not just LAN - it seems like they've "improved" the software that manages reservations automatically and it's turned into HAL. A couple of weeks ago a somewhat different change - probably Cathay's interest in dealing with a BKK-CMB segment - caused my LAX-LHR booking to disappear without notice. Through slight fortune I found out about it a week earlier, rather than turning up at LAX all dressed up and nowhere to go.

Seems like everyone needs to keep an eye on their bookings at least weekly. As someone here tags, it's not nearly as much fun as it used to be.