I heard from a management pilot that despite the email that went out to hold pool candidates, they will be given priority and re-interviewed first. Additionally, it was also mentioned that some weight will be given to the fact that they have already completed the process. Given this information I would expect the majority of the required 80-120 pilots to come from the hold pool, with limited opportunity initially for new applicants.
I'm not sure on the exact date recruitment will start, but the interviews should commence towards the end of Oct.
Good luck guys and girls!