Nope, never an official patch as such. 

The oficial CFS2 website still exists : http://www.microsoft.com/games/combatfs2/ and there is a link there to the enhanced country.cfg file which has pretty much been accepted as the standard, but that really isn't a "patch".

Pretty much everything we complained about in 2000 was fixed by the community as a whole over the years, resulting in a flight sim that is miles ahead of what it was out of the box.