I did try to memorialize the page, they wanted me to fax his ID and death certificate, not going to happen, so the page will sit out there forever or until they have a change in policy I suppose.
During that time, Facebook wasn't shy about reminding me that I wasn't using it, and frequently sent emails suggesting content on Facebook I might want to see. An auto-hibernate or shut down for accounts seems unlikely as it's contrary to their attempts at retention.
I think death is just something that Facebook hasn't really taken the time to establish a good public protocol for; per your post, the behind the scenes protocol of "fax us an ID and death certificate" is probably outside the comfort zone of a lot of people. Maybe it would work for people to establish a series of emergency contacts and grant the contacts a page where a certain number (at least more than one) are needed to confirm the passing of a person, at which point the page moves into the memorialized mode. The process should also have safeguards to be reversible, just in case of pranks, and allow alternative proof methods just in case the contacts are unreachable/unwilling to confirm.
In the USA at least, death records are public information.
https://en.wikipedia.org/wiki/Social_Security_Death_Index
It'd be such an easy lift for Facebook to aggregate, correlate this information (just like ChoicePoint, Seisent, many others).