Bingowings said:

^Not really as the Endor sequences could be set on Endor, the forest moon of Coruscant which serves as a sanctuary for the Death Star shield.

However would it make sense?

That would be like having the Manhattan Project built in Manhattan in terms of Galactic secrets.

Would the Alliance fleet be able to survive a direct attack on the capital planet even without a Death Star (or Two) being there, with the normal level of security?

It makes less sense than Luke's rescue plan of Han.

That way in an eventual ROTS edit, it'd be a nice reason to set a constant Star Destroyers patrol around Coruscant. Right after Palpatine establishes the Empire.