Quote from HunterZGo to curseforge.com and look it up. There's a ticket tracker, but most of the tickets aren't acknowledged so I'm not sure where the best place is to actually raise an issue. I did report the issue of CC not being able to pull down alpha version from WowAce.
From what I've seen mentioned on IRC, the CC is ready for alphas, but the Curse server doesn't send data regarding available alpha versions yet. So it's not a CC issue apparently.