Oh, my home Discord also uses this style of 'lab notebook' channel. They aren't explicitly per-person, but our conversational norm is to not change topics in one channel too quickly. So in a channel that gets one post per week, as opposed to two posts per day, the effect is that it has an owner. Who sometimes changes.
I feel compelled to argue in favor of this state of fluidity (i.e. no fixed owner) because, in part, I still haven't got Medium to click for me. Well, every Medium is its own newsletter, for a start. But Medium posts lack the equivalent of WordPress-style ping-backs. This would mean I can't notify someone I'm directly responding to without also sliding into their comments. Is that really the norm on Medium?
Ultimately, I'm just not going to effort-post if it isn't an organic part of some conversation, even if it's a very slow and drawn-out conversation. Therefore, the critical piece here is not the forum's precise structure of aggregation. It is the pingback whenever someone either replies (inside of the thread), or loudly replies (in the aggregated feed, if applicable).