Do you have examples other than Link? I use Link for all Zelda games because the character literally is just Link but other games I will happily self insert.
What happens when you encounter a game that does not provide or otherwise tell you the default? Yet canonically there is one. See Phantasy Star 2 for example.
I suppose that makes me an old man living in one of those horror films that would be solved in 10 seconds by a mobile phone.
"There I was, visiting a house without internet, genecyst dripping blood menu glowing softly as the Phantasy Star 2 menu asks me to name the main character." "Years later I would learn it to be Rolf in the manual but that was something I could not have known at the time".