Although Nissan has not said or indicated that they are looking to bring back the Nissan Z, the fans are hoping that they would but only if Nissan is willing to take it a few steps back.
No, they do not mean the design or the tech but the shape and size of the Nissan Z. When the Nissan Z was the first release, the vehicle was light and nimble making it one fun vehicle to drive in but the last Nissan Z was far from that. It was bulky and no longer fun.
The fans were hoping that if Nissan were to bring it back, they would make it nimble and fun once more. The Infiniti Q60 would be a good example of what the fans are hoping to get.
Of course, no confirmation has been made yet and nobody really knows if the Nissan Z will ever get a greenlight but it does, what are you hoping to see?