He gassed because he was careless with his punch selection and tried to take the guy out, pretty sure he's learned from that.
Fury has movement so you can't say Joshua would demolish fury just because he KOd a guy who stood straight up, had no head movement and uses none of the advantages a southpaw can have
AJ would knock him out if he landed clean, but Fury is taller, longer, more mobile, and has way more fluid motion. IF AJ caught him, it wouldn't be early, but the smart money would be on Fury on points.
One thing going untouched by a gun-shy old Wlad not fancying the job. A young fast supremely athletic Joshua dialing in the long RH in earnest is a different story altogether.