Yes, I do know. I was here when it was changed. Someone in the forums made specifically the odd thread about it in february, asking why topics now autolock.
It wasn’t a thing before then. Let me see if I can dig it up.
Edit: Even better yet, I found confirmation from a Community Manager:
This was posted in february, 2019. But that was for the Vermintide 2 forums. So I’m sure it was the same story for the Darktide forums. It was introduced later, but doesn’t work retroactively.