I know situations like this are frustrating and the job market in general has a lot of issues, but Who Is Hiring threads aren't a great place to prosecute these topics.
There are links to a lot of past explanations here, in case helpful: https://news.ycombinator.com/item?id=45094555.
This is the case for the vast majority of companies posting jobs here and elsewhere (e.g., LinkedIn) right now. I've been looking for the past 7 months after a lay-off and that exact reply is the most common response I've seen (because it's an automated response). Well, most common after not hearing back at all, of course.