Typically, yes. There have been cases where they did not have the points.
I also have a June UY and will be adding on another 50 points at BLT in January. When I talked to my guide this week, he said it should not be a problem for me to get 09 points when I add on in January as he believes they should still have points. This way, I will still be in the banking window and will bank the points. I have read that usually Disney allows banking during an add on (if beyond the window) but just in case they change the rule, I want to be in a position where it doesn't matter.
If they don't, then I won't add on until June.