I believe the June PDC is designed to get the cronies job positions because some people will not have their current roles funded in the new org and they will be left standing. So the June PDC is a way to catch the cronies and place them into roles because they did not land a job in the 1st half selection process. They just advertise it like it will be a place for everyone to apply, this way Chevron has a legal safety net to defend against lawsuits.
Think about it, how can there be any jobs available for a PDC after a Reduction in workforce in May.