While having some rough days, the IP seems not to be a zombie itself just yet.
Having problems with living, as it happened with Dead Island 2, is somehow ironic when it comes to a series about zombies. As confirmed by Eurogamer, the game is still in active development, confirmed by Deep Silver:
Dead Island 2 is in development at Sumo Digital, and we are excited by the progress the team are making with Deep Silver’s most successful IP. When we are ready to share more information, we will.
It confirms that the team at Sumo Digital is still responsible for the production. Unfortunately, it is unknown when we’ll learn more, but the upcoming E3 2017 might be a proper moment.