indeed there are lot of posts and subjective opinions that silver (I assume ofc as well) sounds better after 100+ hours. I do not keep the links and posts (so I don't have any proof you would say), just mentioned here what I noticed and my personal experience. Not sure if it's magic or something else (some chemical or physical process), but it does work somehow.
How do I confirm that, well nothing in the system was changed before and after a burn in time (~150h) and the difference was quite obvious. This was tested on headphone's cable, different interconnects and speaker cables by me. Btw, when I swapped the cable on my rather inexpensive Denons (D1001) I was surprised how weird the sound became to be, then left them playing for 24-7 in the office and gave them another test and vualaaa, the whole picture has changed dramatically.
Anyway as already has been mentioned, there are no measurements here as well as no physical evidence, just subjective opinions :)