This is even better played back from a digital recording. You need those gold audio cables to truly appreciate the silence.
I personally learned about 4'33" in a music class, where it was performed live -- basically it was 4'33" of ambient noise, but there was a lot of tension if you didn't know what to expect. During the final exam for the class, the professor would play some recording and we were supposed to identify the music, and all of us would start writing "John Cage's 4 minutes 33 seconds" when the professor was too slow to start the next song.
There was also an incident where apparently Mike Batt copied 4'33" and named his song "A One Minute Silence", which resulted in an 6-figure court settlement[1], although later news said it was just £1000[2]. I also heard a version of the story that they didn't settle at all, because John Cage's publishers couldn't prove which minute out of the 4'33" was copied.
[1] https://edition.cnn.com/2002/SHOWBIZ/Music/09/23/uk.silence/
By the way I love 4’33” and don’t denigrate it - the way Cage executed the idea is flawless - which is one of the reasons it’s so timeless. I just don’t think it’s something you can copyright. And indeed, the stories you linked indicate that, though rather than point out the ridiculousness of the situation they simply used it as a money and publicity making opportunity.
Your performance in your location will have a different ambient near-silence, than mine, or any other performance and circumstance. Since the near-silence is the point of the piece, we have different expressions....?
This seems wrong on its face; If I steal the chorus out of a song where it's repeated multiple times and release it as my own, the artist might not be able to prove which instance of the chorus I used.