I have to say, well written article (too bad they only mentioned Beehaw and not Lemmin). Reddit cannot exist without user content and more importantly the moderators who do a hard job for free.
Without moderators, subreddits simply become a free for all, the far west.
I also wrote something along those lines a few days ago. Lots of predictions over a long time span, but it seems pretty realistic with the direction the site has been going for years now.