I suppose the thing to look at closer to get to the crux of the matter would be when things happened and when things were written.

The Oliver North hearings were in 1987. Your source is detailed as Snopes.com so the debunking of the urban myth that Oliver North knew about and named Osama bin Laden as a potential threat in 1987 could only have been written some time between 1995 (When Snopes.com was created) and 20th June 2009 when this response was last updated.

It also should be noted that it is the author of the response, an employee of Snopes.com who more than likely writing long after Osama bin Laden became known comes out with the phrase in this website article that:

"To the extent that bin Laden was known to the western world in 1987, it was not as a "terrorist" but as one of the U.S.-backed "freedom fighters" participating in the war against the Soviet occupation of Afghanistan."

My guess as to timing would be post- 9/11 in 2001 as a direct response to a question asked about the hoax e-mail. I would also state that with marked high credibility that Osama bin Laden was a complete and utter unknown to western intelligence in 1987 - that would describe the extent to which he was known. Tucked away somewhere in Pakistan arranging travel tickets and documentation for foreign Jihadi fighters, why on earth would he appear on anyone's radar? His other function was to act as go-between for ISI and the Saudi Intelligence Service GIP in relations between the Mujahideen Groups of Gulbuddin Hekmatyar (ISI's favourite) and Abdul Rasul Sayyuf (GIP's favourite) - No dealings whatsoever with the CIA.