Ok, not sure how reliable this is, but according to a Japanese site instead of a roadster, there may be a t-top model but it won't be available at launch.
If true, it's a wonderful idea from Nissan to bring this back from the Z32;
it's simple, no breakdowns and no warranty headaches for them (via Google translate so I don't think electrified is the proper word there, probably means something closer to reinforced):
"It is expected that the new Fairlady Z will be equipped with a hardtop roof (T-bar roof) model later.
It is said that the T-bar roof will be electrified with a new structure. Rigidity increases because there is a line connecting the front and back compared to a general open"
https://haru27.biz/26529.html
It's not all good news though, if this site is correct; say goodbye to our wonderful hydraulic steering and hello to Infiniti's Direct Adaptive Steering (DAS)