I did say months ago they were looking at this route!
Notice AA have given themselves an extra 35 mins on ground with ORD. Could of just worked out like this for AA dropping HEL and the new DUB-HEL service offers transit to ORD (no directly bookable yet). 90mins each way. Finnair are starting ORD but 3 weekly over daily AA. DUB could benefit. AA have said they are seeing increasing transit on single tickets.