It was likely to happen given what's been going on at AT&T and Warnerbros. I am surprised that the show did not get cancelled even earlier, given how long breaks between seasons were. Fans are one thing, but execs tend to not be patient, especially in the entertainment industry. Venture Bros was an anomaly in western animation.
Probably not. There were fears that this would happen to the last two seasons, but the show was not affected. They even had Trump as a background cameo, without devolving into sperging or drawing too much attention to him for that matter.
From what I have heard and seen, HBO is not as hands on as other networks, so they most likely won't push for inclusion of woke crap. Larry David was even allowed to lampoon the way LA people lose their minds out at the sight of MAGA hats and have "problematic" people like Vince Vaughn in his show.
Publick and Hammer were working on the show already, so it would be a shame to let this go to waste. HBOMax needs more content, and they are lacking in adult animation compared to their competitors. Worse, another service could possibly scoop up the show and turn it into a hit, like what Amazon did with The Expanse.