[QUOTE=Blueboys999;6860917]The most annoying aspect of the way this happens is that the AA system appears to be designed to do it (and they are aware of it).
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I would think that it simply wasn't designed not to do it.

What benefit would there be in desigining it to dump seat assignments if the aircraft didn't change? The real issue is whether they plan to change the behavior. One of the ADVERTISED benefits of elite status is the ability to get special seat assignments. This should mean that they aren't lost simply because the flight time changed by a few minutes.