I think the issue is that the OP is "trying to get status on AA this year". This means that he/she is using an AAdvantage number for reservations rather than his/her BA Executive Club number which would show as Oneworld Sapphire on the BP.

How about using your BAEC number when making reservations, up to and including printing the boarding pass, ensuring your Sapphire status appears, then have the agent remove your BAEC number and insert the AAdvantage number prior to boarding the plane?

I'm sure there are more experienced members of the board who could confirm whether this will work or not.