I did some more testing and I have a better understanding of this now.
It seems the terms 'ConsentStatus' and 'Personalization' are used interchangably to describe the same thing (which is really confusing???).
ConsentStatus / Personalization can be: UNKNOWN, PERSONALIZED, NON, AD_FREE.
There are two actions related to setting / changing these values:
'Set Personalization' > Allows developer to set these values in project events.
'Show User Consent Dialog' > Allows app user to set these values themselves via a popup window.
In both cases the value for ConsentStatus / Personalization can be retrieved via the MobileAdvert > ConsentStatus expression.
The conditon 'On User Personalization Updated' triggers when the action 'Set Personalization' is used.
It does NOT trigger when the value for ConsentStatus / Personalization is changed via the User Consent Dialog... despite the fact the same values are being changed....
So...
I need a condition that triggers specifically when the User Consent Dialog closes. No such trigger exists as far as I can see?