I understand the article to say, the reason for this is the privacy issue. I feel that Facebook may also have been sued, by people who wanted a family members site deleted. So they create this policy to avoid litigation in the future.
The thing I felt when I first heard this on the radio was.... If Facebook enforces some sort of verification, that the exact John Doe users death certificate must match the date of the FB birthdate....
Many people would not be able to do this in the future, as, most 'kids' lie about their age when they 1st create their online accounts to avoid being the 'minors that they are'.
So later down the road. When Joe Smith (who created his account as a teen with a fake birthday) dies, and his wife tries to get some access, FB will say, 'that isn't the same Joe Smith, so 'no' to your request'