Wrong. Some people from Gainax - I don't know who, someone please correct me, maybe the author (?) - said: "During the seven year timeskip Simon and Nia did what's to be done."
I have also heard that when asked what Simon and Nia were doing in the time between the end of the final battle and when they got home again, someone from Gainax replied, "Well they weren't doing NOTHING!"
The guy from gainax only said that after people kept bugging him. It was one of those yeah sure this happened now leave me alone kind of things authors etc do a lot.
I hated this shows ended, did not need the typical gainax end at all.
Author did say on one occasion that "7 years is a long time." and then on another, they said "Theres two weeks between the final battle and the wedding. They did what had to be done."