Personally, I think Absol should have been in PLA, considering how it's dex entries state "Every time Absol appears before people, it is followed by a disaster such as an earthquake or a tidal wave.", and how Absol can "foretell coming natural disasters", and when those dex entries are paired with how much of a disaster the Hisui/Sinnoh region is in, (even if it's not really a natural disaster which kinda makes the second dex entry I listed pointless towards my statement) I think it's pretty odd how Absol didnt make an appearance in the game, of course, there still is the possibility for DLC which could have Absol in it.