If that schema is installed in the Right Place™, and enabled in the "Metadata Display..." UI, then it might work today. [If not, your test code could feature prominently in a bug I'd write, on that behavior...]
Unlike Prelude, PPro doesn't import dynamic schemae embedded in XMP assets. But if the .xml is in the Right Place™, it'll be available for a user to enable. Annoying: there's currently no way to programmatically enable custom schemae; we're looking into enabling (valid, present) schemae by default in future versions.