How to get expiration date for a trial license for an app published in the Windows 10 Store using Windows.Services.Store namespace?

Question

I have a converted Win32 app that is posted in the Windows 10 Store under a trial license. I am using a C++/WRT version of this code to retrieve app license info, but for some reason the ExpirationDate member of IStoreAppLicense is always returned as 9999-12-31 00:00:00.

Any idea why?

Here's the full JSON that I'm getting from the Store for my app:

{
  "productAddOns":[],
  "productId":"edited-out",
  "skuId":"0011",
  "isActive":true,
  "isTrial":true,
  "isTrialOwnedByThisUser":false,
  "expiration":"9999-12-31 00:00:00"
}