Tommy, I remember reading the exact same thing as you mentioned. However, the booklet in the At World's End Blu-ray had an FAQ about the film which contradicted this, too, so I think it is clear that:
a) Different people involved with the film were saying different things and were not on the...
Sort of, although it's perfectly reasonable for you to have forgotten this, if you even saw it. Will and Elizabeth's son (who retroactively becomes Henry, but was unnamed at that time) appeared briefly in the post-credits scene of At World's End a a 10-year-old, in a non-speaking role. He was...