This is not surprising and has been happening to some degree with AA's Europe schedule for years now around Thanksgiving. Most long haul international travel to/from the US falls off a cliff Thanksgiving week. Business travel is practically non-existent.

Again no surprise that AA doesn't want to fly a bunch of empty widebodys to and from Europe on the lowest demand day of an already off week.

Since covid especially AA has been particularly aggressive in trimming its schedules around low demand periods; A few of the secondary Europe routes won't operate on certain days in Jan and Feb, etc.