I can't remember if John Reilly was in Williamsburg when he was promoted or if he came back from a different park. But you might have to go all the way back to at least him (if not later) to find the last park president who was currently working in Williamsburg at the time of their promotion.
John Reilly was at BGW since his initial hire while he was still in High School all the way up to when he became park president. He then went to SWSD as their park president until he went to Corporate.