The question was rhetorical; I know
where it came from - the writer's bible for TNG, where the character's "original" backstories were written down. But since those character bios weren't set in stone, the original backstories weren't "canonized", if you will. The idea that Picard had already established himself as a captain by commanding a ship for twenty-some years was (probably) in the bible, but since they didn't put it in dialogue, it doesn't "count". The fact that some fans wrote the fanon into the character bios at MA doesn't mean much, since most fans love writing fanon items into MA. You know it's a wiki, right? You know that MA is user editable, and that contacting the webmasters would be pointless, don't you?