I'm the one who made this list and @zeldafan64 is absolutely right - the title suggested in the reply would have been a much better title. Don't judge a list by its headline I guess? If I could go back, I'd change it now. Maybe this warrants a followup.. who would YOU include on a list of unknown strong female characters? Challenge mode: no fair mentioning Samus, Lara Croft, Jade from Beyond Good and Evil, the Life is Strange cast, or Alyx from HL2!
That's the point, though. Maybe "forgotten" was a bad choice of word - they're left despite being good examples. Many say there are NONE and forget to think outside the hit games. It's unfair to say there are no good female leads just because you haven't played the games, you know?
That's a good one no one really knows!