I'm the one who posted it. The link isn't exactly hidden either as its not the first time beta links have been posted. I believe avatar has posted it several times (Wilder's I believe). So it's not really a big deal. Even so, it's best to point out that it is indeed a beta release and could cause issues to any normal user whom decides to try it.
In that case of me posting it, I was trying to get YouTube Center working again with Adguard but also ended up with suggestions from the developer to help Adguard improve compatibility with userscripts in general.