It was put into second-chance pool by moderators. I originally submitted this link a few days ago and today got this (semi?)automated email from HN, an excerpt below:

  The submission "OpenAI Privacy Filter" that you posted to Hacker News (https://news.ycombinator.com/item?id=47870901) looks good, but hasn't had much attention so far. We put it in the second-chance pool, so it will get a random placement on the front page some time in the next day or so.

  This is a way of giving good HN submissions multiple chances at the front page. If you're curious, you can read about it at https://news.ycombinator.com/item?id=26998308 and other links there.