More years than that they came from Sulu or somewhere and made a speedy kidnaping in a costal tourist spot. So they didnt went inland.Just to keep it real and the other side of safety on Palawan, one of our Expat Forum members and a Facebook friend of mine was vacating with his family on Palawan about 3 years ago and I remember the day after they left and returned to the US, the terrorists were working on a plan to to kidnap.
Don't forget you aren't too far from the Eastern side of Mindanao it's just a hop skip and jump and from what I also remember reading these other southern islands they have insurgents working to kidnap from other islands in the region.
Here's some links from that time and also islands in that area were targeted. Abu Sayyaf targeting tourists warning
Local Government reassurance Philippine Army calls for calm
More recent when IS lost at Mindanao, a few came to Palawan to recruit, but they were pushed away fast from south, went to nortth (Taytay) and not ssure if they got caught there or just pushed away fast there too.