Angle snapping was removed as of PID LZ13333. Lower PIDs have angle snapping.
There is no way to specify in online orders which version you are going to get. As time goes on, it is more likely that you will receive a non-angle-snapping version as stock of the older version is depleted. New units have been working their way into the channel for several months, though, so your chances of getting the new one are only increasing at this point.
In retail stores, you can tell the difference between the older and newer versions by the package's transparent closure labels; G400s without angle snapping have the Logitech logo printed on these labels. G400s with angle snapping have no printing on these labels.
Portfolio manager for Logitech G. I am not permitted to discuss future product plans.