I like to have my upcoming itineraries clear of "schedule change", but I hate calling United when I know they have major irregular operations going on just to clear "schedule change" from an itinerary a month or more out.

If you're want to avoid a human because you know what the change is and you don't mind, 1-800-UNITED1 will allow you to accept the change on the automated system. (If you don't have status, this is probably what you already did ).

Edited: whoops, that's exactly what you said you did. Well, other people might not know this trick!