Your initial comment is on-point, except I don't think any of these people are identifying with or as nihilists.
They are invariably politically leftists. Which is where contemporary "bad words and cancel culture" come from.
The irony of being ostensibly "leftist" while flashing a 0.1% lifestyle of "knowing the room service menu at the Ritz by heart" and getting high in first class.
You may be referring to a particular brand of "excuse me for being a degenerate occasionally, but you know my heart is in the right place and I'm a friend of the proletariat" sort of leftism, but it's definitely not a nihilism and they'll definitely parrot the right leftist lines at parties or they'll lose their little perch in a heartbeat.