It's hard to call it a cultural trend when it's a couple famous people removing their library of music from one music service. I don't think it's unethical for a musician to stop working with a distributor if the terms of that stop being acceptable, that's wholly reasonable.

But to try and answer your question; no, I think it's kind of silly. Someone like Neil Young can only do this sort of thing once and trying to use it to deplatform another entertainer doesn't seem to be the most useful (removing Joe Rogan's podcast or whatever won't make a dent in the cause he supposedly is fighting for) and also not particularly effective unless there is a cataclysm of high profile musicians removing their music from Spotify.