I am one of the people who is changing Unsourced England. But I always change it to, say, Unsourced|Wiltshire (if all three BMD locations state Wiltshire). I only ever change it from 'England' to a county, and make sure Unsourced | County xxx is set up already. If the profile just says 'England', I leave it. If it is a Project-Protected profile, I leave it. If there is only one County in there (say, against the birth location) I leave it as England.
My thinking is this: a) profiles are supposed to be in the lowest-denominator category, not a top-level page if they can possibly help it; and b) the PMs are much more likely to get help from people who are concentrating on a specific county and know quite a bit about it. So if a profile was born, married, and died in Lancashire, and their spouse was born, married, and died in Lancashire, and all the children were born in Lancashire, I figure it would be better to have the category Unsourced| Lancashire. It is kept in Unsourced but reassigned from the Unsourced|England page.
There was no 'memo'. I just did it off my own back when I kept coming across profiles which were in Unsourced | England when they had counties in every location field. If I found a profile which only had the name of the town, I looked it up on Google, put in the county, and if the county was repeated enough times on the profile, changed Unsourced | England to Unsourced | County. And yes, I checked.
Well-intentioned. I was only trying to help.