And unfortunately, UA is in a lose lose situation with this type of person for the issue that is being brought up. If they provide the information and then it changes on/before day of travel (because they operate out of multiple terminals at an airport), the uptight person will be upset because they knew everything in advance and now it changes. Or they can not provide the information with the receipt, and the person is upset. UA clearly decided to go with the latter case of lose then the former, presumably as another comment pointed out, people had a hard time understanding "subject to change" and just showed up wherever the original receipt showed.