It is an attempt to not lose European customers that might be tempted to migrate to Europe-based solutions in the current political climate. In the event of a serious trade war (like you suggested) and/or a real war, it gives some assurances; which is smart based on the threats from the current unpredictable and authoritarian U.S. administration.

But it probably started as a way to comply with EU laws more easily, so it works on multiple levels.