That "Description as diagnosis" thinking on the part of doctors is like colic:

"My baby cries a lot for no clear reason."
"Ah, the diagnosis is colic."
"What does that mean?"
"Your baby cries a lot for no clear reason."
"Good to know, thank you doctor."

so now it's:

"My baby suddenly died!"
"Ah, the diagnosis is SIDS."
"What does that mean?"
"Your baby suddenly died."
"But babies don't just suddenly die!"
"They do now—SIDS is a thing now we decided."