In the controller configuration screen, there are 24 Actions that apparently MUST ALL be mapped to buttons. Unfortunately, generic controllers only have 22 (10 + 4 dpad + 4 LS + 4 RS) buttons, so there's no way to accomplish this. Attempts to save the controller config with unmapped actions leads to this error message "Buttons cannot be left blank for any of the controllers!".
I can use these controllers just fine with 2k11, 2k12, 2k13, and 2k14 (all of which I own). They probably work with 2k15 also, but I can't confirm that because I don't own that game.
So I can browse around and look at rating and stuff, but I can't play 2k16 because I can't map my controller(s).

Hopefully, 2k will fix this!
EDIT: Just a quick update, I believe that controllers with clickable left and right sticks will work because you can also map those, giving you a total of 24.