I don't know. I've never heard of it and I read HN daily. Maybe it's because startups don't interest me. Either way, I just think it's funny how these topics, which people clearly want to discuss regardless of what the Buffers of the world are doing, always have to be centered on a company's PR.
For what it's worth, you're not the only one. I read HN for technology oriented news and interesting articles and because I live in Silicon Valley part of the year. I've never worked for a startup and probably never will and I've never heard of Buffer.