At the beginning, I thought Outweek Magazine's Signorile had an outline of when to out people. Example: famous person who had been friendly to the gay and Lesbian community, but had never come out. Outline: wait until they die.
I asked Signorile at a book signing. His response, No, it's more random and based on my thinking when writing in the moment.
I can not put quote there because it was so long ago, but it's close enough to what Signorile meant.