It was 2000, they had been married 2 months, it was a simple flashback. No need to try to make it complicated.

What info did it add? Nothing I can see. They just wrote it that way to make it look like Jin was still alive and off the island - just a trick. The old cellphone was the first clue I picked up on. Then I thought, if she is in labor, why is he shopping for a panda? Then I got it - like the ending of silence of the lambs, when you think the cops are about to save Jody, but its a different house.