Movies Anywhere works by aggregating the active digital access licenses you have participating partner services. The problem here is Sony won't be able to give any active digital access licenses for these movies to users after September 1st, let alone one which allows them to transfer that through Movies Anywhere.
It's typical "you own nothing" logic to the point the companies selling you that also don't even own it.
Sure, but its also run and operated by the rights holders, which they never even needed to do.