The article says the name "bang" for ! "comes from old card punch phenomenon where punching ! code made a loud noise". That's nonsense since every character makes a loud noise when punching a card. I've never noticed any excess noise from ! but I'll check at the CHM next week to see if I can conclusively disprove this.
Not sure about a punchcard, but an old typewriter I once stumbled upon had a noticeable bang on the !, on cheaper paper it even sometimes punched through the dot part of !
Though it may have been just that particular typewriter and tuning would have fixed it.
P.S. Turns out the very old typewriters did not have an exclamation point key at all! One had to construct it using a period, backspace, apostrophe aka single-quote. Good times!
