GEC BC506 Non electrolytic capacitor question

[Kalee20]

It's possible the concern was the very low bias on the electrolytic at no signal rather than reversal as the bipolar ones work with millivolts and some of the electrolytics  would go leaky without sufficient polarising voltage to maintain the oxide layer.

If we assume the transistor is never turned off then the capacitor voltage is about 110mV to 150mV, the Vbe of the transistor.

Yes that's as I see it - the transistor never turned off (for the reasons I have stated), so the capacitor voltage just falling to a very low figure, about 100mV.