No news on Zebra 3. I am in no hurry. Zebra 2/HZ is a classic synth on its own. There is no rush for a next iteration.
I am not a fan of Massive X. Have you tried Demos of Hive 2, Rapid, Serum, Sylenth, and Synthmaster so you can make an educated decision? Maybe even investigate Falcon and try demos of Dune 3, Avenger, and Anima. (Among others). If you are itching for EDM sounds, have you checked out the Zebra DancePack soundset? Spend your money as you see fit.
Thanks for the well wishes!