Perusing various biz and first fares, I am going to guess that they (universally?) exclude rule 35 from I and D fares (discount biz) as well as A and P fares (discount First)

So an MIA-NRT for $6800 RT, or $18k RT and no rule 35.... but spend $29k RT and they'll give you a $12 lunch voucher and a room at a Marriott.

Interesting to see that there IS such a rule (as they take the time to exclude it in many of the fares), it is just that virtually nobody who buys a ticket that would qualify would ever think to ask (nor stay at a hotel AA would select!)