Not a great thing to do IMO... by all means resurface the good stuff to the top of the blog, but why change the date? SEO? I don't think there's a good answer?
Just some helpful advice. Without a redirect, SEO on the old post will go poof.
URL-Rule 1: unique (1 URL == 1 resource, 1 resource == 1 URL)
URL-Rule 2: permanent (they do not change, no dependencies to anything)
URL-Rule 3: manageable (equals measurable, 1 logic per site section, no complicated exceptions, no exceptions)
URL-Rule 4: easily scalable logic
URL-Rule 5: short
URL-Rule 6: with a variation (partial) of the targeted phrase
URL-Rule 1 is more important than 1 to 6 combined, URL-Rule 2 is more important than 2 to 6 combines, … URL-Rule 5 and 6 are a trade-of. 6 is the least important.
And it worked, it reached front page again. I wonder how often then recycle articles and post them with fake dates.