We will just to have to agree to disagree. The 2200 ship Vision barely fits into Baltimore as it is, I don't really know if Radiance will or not. But adding 10-20% more cabins isn't exactly trivial. Moreso as cabins have gotten slightly larger over time. AND when you have more cabins, the commonly used spaces also need to be bigger, such as the theater, dining room, and WJ. Making the foot print bigger means taller, wider, longer. Longer didn't add many for Enchantment- but it would if it had more decks (like Voyager to Freedom). Wider could, but I'm not sure how much wider a small ship can get without problems. And wider also means a ton more interior cabins- which lowers the value of them. Unless the ship is wide enough to have a central parkish area. But either longer and wider will change how the ship can use a dock. Taller, on the other hand....
It's not that I don't want it to happen- I really would love to see a 3000 person ship fit into Baltimore. I just can't see the modern design do it- one with a bunch of balcony decks (far more than the 2 Vision ships have).