It's definitely a follow-up submission and we tend to downweight those, since HN is more interesting when it isn't repetitive. Note that this isn't a comment on the article itself—followupness is an issue of timing, not content.
Usually the best place for follow-up links is in the comments of the original thread. Once enough time has gone by to flush the hivemind caches, then the other article can be posted in its own right.
