Update: you betcha it's a hoax, Rockstar say.
"Rockstar Message: GTA VI Coming 2019" declares a GTA Online in-game notification that's started popping up intermittently. Rockstar's site doesn't mention Grand Theft Auto VI, no trailer announces it, and not even a rumour had hinted at it. You'd think Rockstar would make a bigger deal about announcing a new mega-blockbuster open-world murder simulator, wouldn't you? I would. Presumably this is just a hoax perpetrated by some nefarious hacker. For now: yes, those screenshots you're seeing of a GTA VI announcement are real (like that ↑ one I snapped myself today); but no, that announcement itself is almost certainly not real.
The notices appear in the scrolling feed of in-game notifications, looking like a proper official message. I've heard about this since last week, though largely through memes riffing on the message, then I finally saw it myself today. With Red Dead Redemption 2 not out on consoles for several months (let alone the rumoured PC version), it's ludicrous to imagine that Rockstar are announcing a new open-world murder simulator now - and in this weird way.
I've asked Rockstar's PR peeps for comment, though not heard back yet. Players are speculating about exactly how the messages are appearing in-game. Remember that GTA Online has a terrible infestation of hackers (or 'modders', to use the confusing GTA lingo), yeah? It's probably some of those scamps putting out fake messages.
This is somewhat beyond the scope of the usual hacker tricks, which tend to be more along the lines of spamming murderexplosions, doling out free cash, spawning things in unlikely places, and horrifying pranks with men riding you. But you'd expect/hope it's more likely rapscallions have found a way to post fake messages which look real than it is they've actually infiltrated Rockstar's servers.
Hacking has been a big problem in GTA Online for years. One single hacker can ruin everything for everyone else on the server, not to mention get innocent bystanders banned themselves, and Rockstar are still fighting them. When parent company 2K temporarily shut down modding tool OpenIV last year, that was done in the name of stopping hacking. Over a year later, I'm still seeing hackers regularly. I even had my own account wiped and temporarily banned, I think due to cocking something up when innocently exploring diorama mods, then this morning I met a player teleporting around, doing impossible things, and blatantly hacking the planet in general. Great. Lovely. In short, plfffff I don't think Rockstar will ever win this.
As for things actually happening in the world of Grand Theft Auto, nightclub businesses will arrive in GTA Online later this month.
While I'm here, hey, thanks to the cool BMX gang who toured the city's stunt spots with me (and our rocketbike pal) today while I waited to see the GTA VI hoax message again. Top stunts. Great antics. Good times. You were good. I do like GTA Online when hackers aren't pinballing me around.
Disclosure: like half the population of Edinburgh, I'm pals with a few Rockstar folks. They are EVERYWHERE.