No, they either give you the points for the UY you are currently in or they don't sell you the use year. That's how it's always been. That's how it has to be.
If you call today and they agree to sell you an Oct or Dec UY, they have to give you 2019 points.
However, now it looks like you have to make sure they are going to bank them for you past the deadline.
Most likely, they will simply make you wait until Oct 1 (for Oct UY) or until Dec 1 (for Dec UY) to buy and then you will start with 2020 UY points.