For any ESLs or neets out there that are genuinely confused: Open Auditions just means they are accepting auditions without plans to act on them at the moment. This is different than announcing that auditions are opened for the next generation of Holostars. Compare it to a business saying they are "accepting applications" as opposed to one posting a real job listing. Companies do this because they aren't sure if they want to dedicate the resources to opening a new position and want to see the available talent pool before making a decision. It has actually already been a thing this entire year and the post is only notable because they are redirecting holostars auditions to a different website.
https://twitter.com/hololive_en/status/1476445784862498816