That is correct. You log in any C&R qualified firearm you purchase while holding an 03FFL regardless of whether you gave a copy of your license to the seller or not. C&R firearms owned prior to having an 03FFL are only logged in if you sell them while you hold an 03FFL. They are then logged in as "acquired prior to license" and logged out in the usual manner.
To add a bit more, this is what I assume people mean when they refer to "using" their C&R license or not for a particular sale. But if you have the license, there is no such thing as using the license or not, since the logging requirements apply no matter how you acquire your new C&R guns.