No, you can not see the PWM outputs in the watch window using MPLab sim ( of course you can single step through the program and see the logic level of the specific port pin go high and low). A better way to do it is to use the Simulator Logic Analyzer, where you can see(apart from a host of other features) the actual clock cycles that the high and low pulses stay for. But bear in mind that MPLab Sim is not a dynamic simulator i-e if you use run continuously, you would not be shown any register/pin changes during execution, only after the execution is paused or stopped, any value changes will be shown.