That is news to me (I seem to recall that it was open til midnight awhile back). A quick perusal of the current updated Felix website does say that it’s open 'til 11PM on Friday & Saturday these days.
My point was that grabbing a seat at the bar later in the evening is best the way to go. If I wanted to maximize walk-in success, I’d try for a seat at the bar on a Tuesday at 9:30pm, or something to that effect.
n/naka remains reservation-only.