For example, there are a number of artists who seem to glorify killing police. Should we consider it normal that big time artist XYZ would feel the need to remove their music from the service? Yes, it would be their right (I don't think anyone disputes that)... but... is that a good cultural trend?

To my eyes, this looks more like tribalistic posturing than some sort of principled stand for something.

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.