Final answer:
The statement is true; pyDefault data transform is invoked when a new case is created, and it then invokes pySetFieldDefaults to set default fields.
Step-by-step explanation:
The statement is true. In Pega systems, when a new case is created, the pyDefault data transform is invoked automatically by the process. This data transform's purpose is to set default values for properties when a new case is instantiated. Following this, pyDefault invokes another data transform called pySetFieldDefaults, which can further set field values or perform additional initialization tasks.