The check-in desk agents asked me to show ID at LGA and ORD this weekend.
After asking for my ID, the ORD agent proactively showed me this site on aa.com and said that this is the route I would need to take to avoid showing ID. Perhaps I missed it, but I don't see any reference to this upthread other than the mention of "machines."

https://www.aa.com/i18n/travel-info/security/mobile-id.jsp