He avoided GGG since 2012 for obvious reasons. He is too proud to lose against a smaller guy. He rather gets knocked out at HW but he can always say that it wasn't his weight class.
Gennady will never fight him, irrespective of weight class. he wanted nothing to do with him when he was campaigning full time at SMW, during a period where his trainer said no one from 54-68 can beat him. What makes you think he'd fight him if he went back down to 168? Let him enjoy the fruits of his mediocre labor with his fight against a JMW and than he can take on the big bad Billy Joe Saunders so he can unify the great, deep talented MW division. Cleaning up such an ATG talent pool must feel really good for him and his handlers.