I just booked SJC(San Jose, CA) -->CDG for ~$505 per person in June on aa.com all on BA metal. Booking code came up O which is strange. Thought that might be an award ticket booking class.
AA CSR said no upgrades with points or cash is allowed from AA's side but I should try contacting BA in the AM. I'm guessing we are stuck in the back if we want this fare. Maybe upgrades at the airport would be possible.