Years ago Maher had an outsized presence in the larger public conversation. Now he has a devoted following which will fill his studio and watch his show on HBO and virtually nobody else. As long as HBO is happy with those numbers Maher has a show. Since his snippets rarely escape out into the larger social media conversation we don't have to care.
Will AT&T try and censor his content? When Maher was transgressive with out-of-mainstream topics like cannabis legalization, same sex marriage, and atheism, he was being transgressive within his comfort zone. Now that all of those are mainstream if he wants to be transgressive just to provoke he's going to have to go to something beyond his own values. He doesn't need to take that chance.