I was looking around on Amadeus and noticed something that I thought was a bit strange. Why is it that on some category routes all classes of service are listed as being available on the airline not operating the flight, while other times there are typically no first or business seats available. Examples:
UA8837 ORD-FRA there is no first, but listed as LH431 there is.
LH1419 PIT-FRA there's no business, but as US782 there is.
AA7614 ORD-MAD has no first, but IB6274 does.
Is this mainly so that the airline operating the flight is able to make money off of their premium product and that way the category airline isn't reaping the benefits of the premium seats? Or is it some other type of regulation.