A user over at NeoGAF found a tweet from Oddworld Inhabitants Director of Development Stewart Gilray, where he noted that they had managed to get Abe from the Oddworld series in as DLC for Playstation All-Stars Battle Royale. But that it had later been cancelled.
With Sony severing the ties to developer Superbot Entertainment, the game is now in the hands of Sony's Santa Monica studios who tweeted that there are still plans to do DLC. So it essence, there will be more DLC just no Abe from Oddworld.