In other words, Ed isn't totally off the sauce at the time of writing (as evidenced quite adequately by his NAMM performance), and they don't want to run the risk of being sued by the fans because one of the band was too pissed to put on a decent show, as happened to Creed a few years back.
It's just another in a long line of false starts. I was flicking through an old Guitarist from '04 the other day in which Ed was touting 2004 as being VH's comeback year, which as we all know, it wasn't.
I hope he can kick the booze, I really do, but I can't help feeling the moment has passed for VH now.