Don’t know when it started, but at least 30 years.
Cause of death is a must.
What does that even mean: "Cause of death is a must"?
Are you referring to a cause of death being listed on the death certificate? Then yes, a
cause needs to be written. However, that does not require an autopsy in significant
majority of cases.
Again I am not sure where you are coming up with 100% autopsy requirement? Heck, even
cases where the law requires referral to the coroner it is entirely in the purview of the
coroner if they wish to take the case and subsequently do an autopsy. Autopsies are
expensive and very time consuming. Nobody is doing any unnecessary autopsies for free.
-Ali