Coruscant is absolutely huge. A planet that is completely covered as a city. Considering the size of any map already included in SWBF2 or SWBF1.. they only represent "slivers" of the entire planet. To create an entire map of the planet would be a huge endeavor.
I like the idea. I love coruscant. In the PC version, there's a mod map "Coruscant Streets" at GameToast. Great map and it is a big one. But even that is basically just a few city blocks. You have to load it up with bots to make a good game of it. If you don't load it up with bots... you spend too much time looking for targets and the CP's are too easy to take. That's one problem with huge maps.
You COULD solve the problem of getting around the planet by introducing flying vehicles in the maps like they had in SWBF1. But you're also introducing a vehicle noob factor which might ruin the game play on the ground...
I guess the real question would be "how much to scale would the map be?". One person's entire planet might be just a "representation" of the planet to another.