According to Bloomberg journalist Jason Schreier and developer Phil Hooker, work on individual elements of the game continues despite the approaching premiere. The authors' goal is to release the most polished product possible without the need for urgent patch fixes.
If Rockstar believes that the game has not yet reached the planned level of quality, the team has to continue working. This is about the final refinement of one of the biggest game releases in recent years.
Phil Hooker also noted that the development of GTA VI never followed a pre-established template. The scale of the project requires careful verification of all interconnected elements: changing one mechanic can affect other parts of the game.
Before release, graphics, story dialogues, NPC behavior, and numerous side quests need to be checked. The final refinements should improve the quality of the game and do not in themselves indicate a delay in release.