Indeed, it would make sense that musket volleys evolved from archer volleys than being spontaneously invented as a tactic for a weapon that was competing with the bow.
One thing that I don't enjoy from COUP is he often demolishes ideas that approach strawman territory (is a barely coordinated order to start shooting a volley? or does it have to be something else), but I understand that from his perspective as a teacher, he has to disabuse his students of all the nonsense tropes they pick up from tv shows and movies.
The most obvious reason they practiced volley firing for muskets is the large amount of smoke they produce, once one person shoots the rest can't see where they would fire so you want everyone firing at once so they don't block each other.
So there is no reason to believe the practice evolved from anywhere, they is no world where they didn't volley fire with muskets that produce a lot of smoke since its the obvious thing to do.
After photography for sure, the Zulu used them extensively when beating the British.
Where do you think current students get their misinformation? A lot from TV?