I've always been torn about Hitler's portrayal in this game. For one I appreciate he's shown as a gross delusional doofus who pisses in front of people and has melted brain syndrome. He's depicted as deeply unhappy and unwell even though the Nazis have won and conquered Earth, the moon, and Venus. The core of Nazi ideology is a very sick weird man who has no idea where he even is and lacks the capacity to enjoy his victory.
But at the same time it felt a little wasted. He only appears in one cutscene and is largely irrelevant to the plot. It's one little funny haha scene where Hitler could have easily been any other Nazi. I can only assume this is so the game could get released in places like Germany where they scrub the Nazi references soemhow. Some kind of law about how video games aren't considered artistic under German law and thus don't have the right to depict swastikas, Hitler, etc. I believe he's not Hitler in the German version, just some weird movie guy.
I mean if you show Hitler in a Wolfenstein game the player should get to kill him. It doesn't even need to be a boss fight like in some of the older Wolfenstein games. Just let me throw a hatchet into him, come on. BJ has had a shitty life and he deserves to kill Hitler.