When data pages are referenced, they will be created if they do not already exist or if they have expired. Can you provide more details on your use case and why you are trying to check if it is there but do not want to create it?
Another idea is that rather than making the when rule on your section check for if the data page exists, check for if a value on that data page exists. For example, maybe you could show the section only if D_Customer[.pyID].SSN exists with a value? Alternatively, if the reason that the data page is empty without real data is because it is populated from a service call, you could do a check that the data page exists and does not have page messages on it.
Can you please provide the D page scope, Structure and before checking the When condition the d page referred anywhere? . if you are using page exist function its create a page and give a result as true. Better try for property exist like D_Customer[Param.pyID:pyWorkPage.pyID].SSN.