Understanding Fare for Connecting Ticket w/ Diff Cabins
 

I know if I looked at the fare basis before purchase, I would know what I purchased but I didn't. I have a one-way ticket with two connecting flights.

Flight #1 : Short CRJ hop Fare: V
Flight #2 : Long transcon booked in biz Fare: I

I'm likely running into IRROPS for these flights later today. What will the agent rebook me in? Coach or biz? How do agents address split fare tickets like this one? Will they count the fare class on the longer leg?

Depends what alternate flights are available. If keeping the same routing then all should be fine. If selecting a different routing then they will prob do it in a J type inventory. Am guessing u have that V fare as the CRJ doesn't offer I inventiry.

Following up: I was just rebooked through CLT. Both planes I'm on have a first class cabin. I'm booked in it on both flights.

Good to hear - it was likely a V/UP type fare that booked in I where I (and V) were available and V where I was not (the CRJ).

AA should re-book you in any available first/business class inventory in IRROPS. The main issues arise when there isn't any FC available unless you want to wait and you take the "voluntary" downgrade to coach, AA's refund mechanism kind of sucks, which is why it's important to screen shot the flight search result page showing the coach and biz fare side by side at the time of purchase in case you need documentation for AA, the DOT, or small claims court if it gets to that point. (That said it's also not difficult to calculate the difference on these /UP fares with Expertflyer) if you have three original fare basis code.