So, I'm trying to book a trip for the fam to MCO. I book wife and son on reward ticket and myself on a revenue ticket.

Since I'm SE, preferred seating is supposed to be free. I call after everything is booked to link the PNRs and change assigned seating. AE can't access the preferred seats and directs me to an AC agent. AC agent says they won't change my wife and son's seats to preferred seating (next to me) because "we're not on the same PNR". I'm a bit surprised, as this doesn't make sense to me at all, so I look it up on the AC website. Indeed this is the policy.

I just don't get it. Does this make any sense at all? I decide to spend $800+ for a ticket for myself instead of using my miles (yes, I need more legs for status this year), but in exchange for giving AC revenue for this trip, I'm asked to fork over more $ for seats which otherwise would have been free.

What's the deal with this?