Imagine if that was someone's wake-up call. But, yeah, as you said, this is a very tricky thing to account for and balance/circulate. I've been marveling at how space stations or submarines do their atmosphere for years, but it'd never occur to me in a club. A colleague from chemistry department once told me he detected an argon leak by noticing the air seemed to get dryer by the minute. Left station to check the read on the wall, started hyperventilating, connected the dots in time.I wrote 'em to see how they'd gotten around the toxicity problem.
I am one hundred percent convinced it was someone's wake-up call. Remember - this is the industry that brought you the Fyre Festival. The one article I saw mentioned that they had a couple pass out at one of the hotter clubs and realized that maybe there weren't a whole lot of safeguards associated with it. But then, this is the nightclub industry, so their Wikipedia page is still up. Which probably prompted copycats. And hey - maybe for $85k someone will actually pay for safety monitoring.