We can't pass any judgments on "vibrancy" here due to the questionable methods by which this Youtuber captured these videos. This is not a guy you can trust when it comes to accuracy.
None of these versions will be "natively" washed out. Whether it appears washed out will depend on variables that you can control, basically.
That won't the case, believe me.
I agree. Which was my point. We've seen plenty of direct feed PS4 walkthroughs of AC4 (I mean PLENTY) and the colors always looks vibrant. It's pretty obvious the YT video itself, is the cause of the washed out colors.