This is just my opinion, which you can take or leave.
Although I don't wish alcoholism or drug dependancy on anyone, personally I would feel more confident if the facilitator, experientially, knew what it's like to hit rock bottom, make the conscious choice to stop drinking, and feel the withdrawl symptoms firsthand. The struggles as many of us know don't end there.
I think, and I could be wrong, the fact that we share similar experiences is what makes this site and AA meetings, etc. so helpful. We are all going through it together, We can all relate, and hopefully the facilitator has been there before. Although I haven't been to AA myself, I have been in group therapy sessions with a facilitator.
All this being said, I would guess it is possible to be a good facilitator/councelor having not had a personal background in chemical dependancy. Just don't go into the job wanting to "fix people."