Three hours later and have you realized that CoolAssPuppy (Twitter itself) hasn't answered any specific question? If you write in HN you expect a conversation happening.
Probably because Twitter's PR people probably reached out to him and told him he wasn't helping anything and needed to stop posting. I wouldn't be surprised if they walked to his office and unplugged his keyboard.
It was bad. He posted something that made him look like an idiot or a liar. I'm not saying he is either one of those, but the post he wrote makes almost no sense when compared to the e-mail presented in the post. It is like he didn't even read it. If he was trying to say that they never sent that e-mail, then that point wasn't clear. I'm sure he had the best of intentions but it really blew up in his face.
I used to subscribe to a service that emailed me when I got a response on HN but that stopped for some reason. HN Notify I think it was called. What do people use apart from refreshing their own comment pages?