Only downside I've ever seen is having to put up with all the whining and moaning from those who happened to be aware of the old thread. I never am, because this type of exchange always takes place on the first time I've seen an article.
Not to worry though. Those whining and moaning about a dupe post are merely serving to bump the thread back to the top, which I am sure is how I happened to stumble across them.
This post was a good story and it brought a smile to my face.
Funny, the posts that make me smile are the ones that somebody invariably complains about.