In a new Rockstar earnings report, it revealed that it expects "major things" and "new record levels of operating performance" in its next fiscal year. For context, that covers March 2024 to March 2025. It seems likely that the earnings report's expectations are based on the release of GTA 6 and possibly its own Online mode, placing it somewhere in that bracket.
Leaker Tez2 claimed in March that GTA 6 has a not set-in-stone release date of holiday 2024. This means it could be pushed back into early 2025. That lines up with the earnings report's expectations for the next fiscal year, as Rockstar claims it's "positioning our business for a significant inflection point", which is to say a huge turning point likely spurred on by a new release (as reported by VGC).
Insider Gaming backed up Tez2's claims, but the two believe that the holiday 2024 release might be an ambitious goal. They reported that there may be a contingency plan in place to ensure it sticks the landing. Rockstar could allegedly hold back parts of GTA 6, labelling them as DLC for a later launch.
Rockstar's earnings report also mentions an "exciting next chapter" that the company is looking forward to. This is unlikely to be anything tied to GTA 5 or Online given that it has been five years since Red Dead Redemption 2 launched, which itself came out five years after GTA 5. GTA 6 is clearly imminent, something backed up by several leakers and insiders at this point. Releasing in 2024 would mean that it has been in development for six years, matching the development cycles of the last two Rockstar games.
As for what will happen to GTA Online--we simply don't know. It may wind down like Red Dead Online to minimal updates and content, or it may carry over to GTA 6's own version of the mode. Until Rockstar reveals anything, we can't say.
Also backing up the claims of a 2024 launch are Take-Two's financial predictions from January of last year. It said that it expects to grow at an annual rate of 14 percent over the next three years, which analyst Doug Creuz said would translate to $9 billion. They read this to mean "a likely GTA 6 launch in FY24". The fiscal year 2024 ends on March 2024, backing up claims that it will launch next year, but given the alleged insider information from leakers and the new earnings report, March seems far too early. It looks like we'll be getting our hands on it in the holidays, if it isn't delayed to early 2025.