Fast Track vs Priority Review: please see #msg-10124239.
Accelerated Approval is something completely different from the above. It is conditional approval of a drug based on a surrogate endpoint pending additional clinical data to show that the drug confers a bona fide benefit in survival, quality of life, or some other indisputably important metric.
AA allows sponsors to pursue surrogate endpoints for approval. In other words, AA has an impact on the conduct of the clinical trials and registration program.
Priority review, like the rolling NDA / BLA, is simply an administrative affair that helps speed up / streamline the paperwork and decision-making process. It has no impact on the registration program or the means by which the clinical trials are conducted.
You do not need Fast Track to open up the possibility of priority review.