In a stealth change that went completely unmentioned by the patch notes, there's now a Lucio-specific menu option on the PTR that "alows" for backward wall-riding.
This will allow Lucio players to strafe back and forth on walls and will be especially useful in defending on payload maps. So not only will this allow Lucio plays to drop the beat, they'll be able to moonwalk horizontally as well.
You can turn this feature on by going to the options menu and going to the control subheader. From there, scroll down to Hero, and it's the fourth option.
And here's the video proof, thanks to Admiral Sirius: