P-Channel Mosfet switch and Capacitor Discharge on Drain
There are a couple of potential harms:


The inrush to the capacitor when the PMOSFET is turned ON. Some calculation is needed to be sure that the peak current is not too high. I guess that's no problem, but it's better to be sure.
Does the power-on reset circuit work if there's some voltage left? A resistor could discharge it surely. I do not know if any reset circuit exists.
In the past connecting the power on later in a part of a system could cause malfunctions and even smoke because some parts didn't stand input voltages during the power-up. But this is probably no problem with properly designed modern parts. Again: better to be sure!