Correct. On import we don't automatically create free-space profiles for sources. Instead, we integrate each source into the person's profile. That is duplicative. One source might be used 100 times in a gedcom, but we put it on 100 person profiles instead of creating one free-space profile and linking to it 100 times.
On export, we don't currently include free-space profiles. We should and that's on the to-do list, but it wouldn't do most gedcom users much good since other systems wouldn't know what to do with them.