On page 30 one of the characters says, "oh my god." I find that ironic because the student attends a school named after Heinlein and Heinlein was not a believer in gods. Apparently in the story mankind has not advanced as far I thought. Had I authored the grafic novel I would have subvstituted the word science for the word god. I make an effort to do so but sometimes I catch myself saying god.
Regardless, there's likely to have been language shifts. But generally profanity and other emotional phrases are used without thinking of the meaning. I mean, if you say "shit!" when, say, you realize you're being audited by the IRS, chances are you're not talking about fecal matter. Unless you've just deposited some in your drawers. And even then, chances are you're not referencing the brown baby you just dropped.
That's assuming people do rid themselves of religion over time. Many fellow atheists don't seem to grasp that a lot of religious people are
casual about their religion. Even if we learn enough about the world to travel freely in time and space, all it would ever discredit would be individual religions. Not necessarily the concept of deity. It's slippery, that concept of deity. Hides in the unlikeliest of gaps.