The verbiage on the PD partner page has been like this (i.e. confusing / vague) since this last summer, nothing's changed recently. There is a Porter Airlines flights already booked elsewhere section that says flights booked on non 027 ticket stock earns miles, but the Terms section implies it must be on 027 ticket stock.

From the main PD thread, the majority of data points (including my own) report that miles are being earned from flights on non 027 ticket stock.