They renamed a post of a few days ago (perhaps with a few changes) and resubmitted it with the new URL. IIRC it's OK to resubmit here a post a few times if they don't get much attention.

When I see a repost, I like to include a link to the old submission, because sometimes the comments are interesting (or more interesting than the post itself). In this case it only got one comment: https://news.ycombinator.com/item?id=9253624 (11 points, 3 days ago, 1 comment)

Also, I prefer the old title "The story of how Webflow got into YC", the new title I too linkbaity.