It sounds to me like Oppo had problems sourcing the ABT video chip in the 83 and/or a few other pieces, so they had to make adjustments. Not sure why they had to drop the 80, but I bet it was due to the same sourcing issues.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70