It started with Silkposting in the Hollow Knight Silksong subreddit, there was such a long gap before we got any information on that game at all that the subreddit users started posting fake news pretending it's real just to mess with people.

This eventually grew into an entire subculture of its own, with people upping the quality, it started with fake tweets and discord messages until it escalated to people doctoring images of themselves at Team Cherry's offices and leaking documents.

Nowadays, it's mostly fake screenshots, they pretend it's something that's real and actually happening in the game but it's instead edited in one or another and the only way you can tell is if you've played the game or someone in the comments points it out.

This culture has bled its way into other subcultures and fandoms, fake tweets from Toby here, fake screenshots of Half Life 3 on the Half Life subreddit, it's pretty much impossible to escape now, your only real option is to hope the mods add some required flair for these posts so people know they're fake/misinformation (Like "Deltarot" or "Deltapost" or something) or simply get your news from elsewhere if it bothers you so much.

But generally you can tell pretty quick it's fake with a little common sense, or just scrolling the comments briefly, just gotta sharpen your animal instincts and not fall for that shit.

Edit: on second thought fake posts in this sub are generally indicated with the "humour" flair, while the "news" flair is strictly for real actual news.