I thought that was where the white smoke from the Vatican comes in. When a pope dies, he lies in state and when a new pope is elected, the previous pope is cremated.
That certainly wasn’t the case with Pope Benedict, he resigned and lived for about 9 more years. Living that long has raised questions about his claim that his health was why he resigned since most Pope’s serve until death.
Oh, also, cremation of Catholics was forbidden until 1963 and has rules about how it is to be done as it was a pagan ritual.