Sardelac Sanitarium versus wiki Feedback portal

ArenaNet doesn't read any suggestions in Sardelac (link), but they say (link) they do read (some) in the Feedback space on wiki. Should users aware of a suggestion simply ignore suggestions in Sardelac that already exist in Feedback? The Sardelac thread in this case doesn't really serve any purpose for promoting a suggestion. Is it helpful to link the OP in Sardelac to an existing suggestion in Feedback? Or is this the best function of the Sardelac forum?

For example, this thread has a similar suggestion on Feedback here.

Yes, they should be aware. I'll add something about this to the guidelines sticky. Thanks for bringing it to our attention!

And I don't see anything wrong with being helpful and pointing out the suggestion on the wiki as long as you contribute to the thread with your thoughts on the suggestion.