Non-political
I can understand if you don’t hear this argument that I’m contending regarding the parameters of Minhag, but I don’t understand at all why you are saying that its internally inconsistent for me to argue this way.
By the way, after doing a little more research and iyun, it became more clear that not only is the issue here dependent on how many people it takes to establish a minhag, and for how long etc, but more fundamentally on the basis for following Minhag Yisrael in general: Some Poskim seem to understand that it is only because it acts as a proof that there must have been a legitimate Psak by a Rav in the first place that initiated the whole Minhag (and the Psak just became forgotten, and now ‘revived’)–in which case you would not have that over here, as there doesn’t seem to be any Rav who initially was ‘machshir’ the production of this song with full knowledge of its origins. Other Achronim from later centuries however clearly express the idea that the basis for following Minhag Yisroel is that Klal Yisrael is zoche to a special Hashgacha from Shamayim, and that if a sizeable group of Yidden act in a certain way (again, it obviously has to be justifiable within halacha, like here where there is a daas yochid and another sevara to rely on) it automatically has the stamp of Heaven on it being machshir it. What’s considered ‘sizeable’ would still be up to the Posek to assess, along with this fundamental issue of how much inherent chashivus to attribute to a Minhag Yisrael.
A fascinating sugya to the say the least!