Noob question involving BA Avios ticket on AA Metal:

I booked a MIA-GRU for late October using BA Avois on a AA flight, in premium economy. There was no business class availability showing.
Now here is the AA availability on redemption miles showing for my flight. Unfortunately this business class availability on their site, is not showing to the partners like BA.

My question is - is there any way for me to upgrade my ticket? Either through Avios, or if there is an upgrade bids/last minute deals, or AA upgrade vouchers that I can beg/borrow/steal..