Good point Alex. I believe that you are correct. Now that I look at the screen shot I see that the points and problem source are in the problem itself, and that was changed in 2.16 as well. So the tikz will not work.
However, the outer parentheses that I saw will still be resolved by using TeX instead of the string. I am not sure why you are not seeing those. That should be the same for 2.15.
However, the outer parentheses that I saw will still be resolved by using TeX instead of the string. I am not sure why you are not seeing those. That should be the same for 2.15.