A ship like the J would have been built to last too, maybe centuries. You don't build a ship that big for the pitiful run some of the Enterprises got. I could see them doing a series where J as a multi-generational city-ship went to one of the Magellanic Clouds and only now was coming back, if we ever got to see trek past the point of SFA, again.The Enterprise-J, in my head canon, still happens by 2550 and looks just like it does in "Azati Prime(ENT)." It's a case of Trek tech that's destined to exist whether or not there's a Delphic Expanse that's overrun most of the Milky Way Galaxy and a war with the Sphere Builders. Same design, same external appearance, same registry and dimensions. Just in an era of peace or, at least, no war with transdimensional aliens who build huge spheres.



