What are you actually worried about? In what way(s) do you think GTA 6 will be bad? Since we don't know what the game is, how do you think previous GTA games would differ if the same apparent creative standards of 6 were applied to them?
First: I never said it would be bad, all my negative perceptions could become reality and it could still be good. Second: you're right, I dont know what the game is going to be. I'm just feeling which way the wind is blowing and making a prediction.
That said, your question has really already been answered by all the other comments in this thread saying "yeah sure they're gonna change this or that in GTA 6, but you're ignorant if you even liked those things in the first place". That would probably be many peoples exact response "Oh, you want them to keep those things? You must be a shallow, bad, person." These responses can be summarized with 3 letters, but I wont go there.
There is plenty of humor that can still be done obviously, such as the anti-corporate humor in 5, the anti-cop humor in SA, etc etc but I want you to brace yourself, because being an honest person having a good faith conversation, I'm going to get into specific things, many which I do not condone, but were in previous games, but only because you directly asked.
Could you have a character like OG Loc from San Andreas who is a very unintelligent rapper who the game openly makes fun of in his various radio segments through the game? I think maybe. Could you have a character like Trevor who openly talks about SAing people? I dont believe you could. Could you have blatant racial stereotypes? I dont think we're going to be seeing that. How about objectification of women? Lol, not happening in *current year*. You know that thing where you pay a hooker, kill the hooker, and then rob her dead body to get your money back? What are the odds that you'll be able to do something that psychotic in GTA6? How about even something as basic as going to war with a haitian gang and exclusively killing hundreds of black people? You can bet your ass that gang must be multiracial. These are just things off the top of my head.
Just to clarify, I do not approve of discrimination or murder or other serious crimes, obviously.
My prediction for GTA 6: There will be constant 4th wall, self-referential moments and meta commentary on how bad and ignorant the previous games humor was.
These posts are getting long, I know.