No, the CS pin outputs a current which is a ratio of the output current. My copy of the datasheet say it puts out 1/11370th of the current. A resistor will turn this current into a voltage.
Note that current can be negative, so protect your Arduino input with a resistor.
The current will closely follow the PWM, so to measure the DC equivalent current, you need to add a capacitor to filter the high frequency and ‘average’ the voltage suitable for the analog input.
I’ve found this circuit works well, where CS1 goes directly to an Arduino analog input.