So the same MO as always. To take a stranglehold of the internet. "Creators" or "influencers" or whatever buzzword will be all over this as it's an opportunity to monetize. I'm sure reddit corporate will be taking their piece of rent seeking of course.
The bigger implication that everyone always ignores is that this is going to lock users into the walled garden. Up to now posters have been driving people off site. The comic artists are a good example. They post their comics as image posts. They direct people off site to access more content. They will no doubt jump on the chance to have a paid subreddit. This is an attempt to kill off whatever sites the artist use. If they had some other service providing monetization then that company is probably panicking a little right now.
It started with gmail IMO. That was an early milestone of the evil empire. They announced mining your emails to build an ad empire. I remember being bewildered that nerds on forums were going nuts over 1GB of storage. What a shit trade off I thought. But what did I know then especially relative to the expertise of internet nerds.
Gmail was launched around 2005 which means the concept was in development several years before. That puts the timeline around 2000 probably. Google was evil from very early on.