This issue appears to have gotten lost. I've confirmed that the reported behavior still exists and actually occurs if the fulfilmentPreference value is incorrect, as well. For example:
Attempt to post the following payload to folio-snapshot to replicate the originally-reported behavior:
Ensure that the item with barcode: 653285216743 is in status "Available"
To replicate the issue with "fulfilmentPreference", attempt to post this payload:
Again, make sure the item is in status "Available"
If you attempt to create a request without a request date the service returns an error and does NOT create the request but it does change the item status to Paged (for a previously 'available' item)
using an available item without a 'requestDate':
The return is:
"message": "may not be null",
However, the item status is changed to Paged