It did in February. I can't see them getting rid of it, it would slow down the line.
Be aware though, that the single rider line gets longer exponentially with the stand by wait time. If stand by is 30 minutes, you'll most likely fly through single rider.... Because it's mostly people who are going on the ride alone. Once the stand by line builds, more and more groups of people decide to split up and get in the single rider line - which could actually cause you to wait longer than if you had gotten in stand by. But most of the time, you'll rider faster with single rider.... How fast depends on how many others had the same idea.....