The lack of pressure suits tells us that at the least there is a force field and some sort of gravity. But the best evidence is that Trek lore has always been that the Enterprise was built in Starfleet's San Francisco Shipyards. I would consider that to be a reasonable bow to the fans of Canon Trek. While they would not have to follow the Treklore, I don't see it as a negative and would probably help endear them to the fans a bit, who might then look the other way a bit on things like an increase in the ship size. But again, this is all a guess based on canon lore, but I see no reason why they wouldn't bow to tradition on this point.