Certainly not a coordinated marketing push. All of the recent Rust posts on HN don't come from any official venues. It's just random community members writing about Rust, and HN upvoting it.

There was a flurry of Rust posts about "why Rust" near the end of the year, which was somewhat "coordinated". In the sense that Steve wrote a post and this triggered a chain reaction where all kinds of folks wrote about related topics. Completely unintentional, just happened. Most of those posts did not make it to HN.