It's not detached. Even if a thread is detached by a mod, in my experience it appears at the bottom of the post. A new feature was rolled out recently where som

It's not detached. Even if a thread is detached by a mod, in my experience it appears at the bottom of the post. A new feature was rolled out recently where some get rolled up and hidden by default. They're accessible by clicking the [+n] link in the header of the top-most comment of the thread. That's how this subthread appears to me currently. I'll look for the comment where I saw more details on this. Edit to add: I haven't been able to find the comment where this was mentioned. It was within the past couple of months, though.