Voltage drop at gate of pmos (or nmos)
A MOSFET gate looks like a capacitor.  The resistor will slow down the MOSFET turn-on and turn-off, and it would protect a delicate driver pin (unlikely, but possible), but in the end the thing will still switch.

In that circuit the resistor is to slow down the MOSFET switching, to reduce the speed that the drain voltage changes, which in turn reduces EMI at the expense of a loss of efficiency.