I suppose there are all kinds of GRADES of live rock...lets see...
You can have base rock, dry, nothing on it. As long as you have proper water paramiters and lighting eventually you will see it become live and in time will grow coralline algea on it. Take about a year to 18 months.
Uncured live rock can have the bacteria on it, some plant life, and or other algeas, perhaps even some coralline, it may have to be cured by the person who purchases it before adding it to the tank to prevent unwanted spikes in ammonia.
Fully cured is ready to go into the tank, may or may not have coralline algea from some to completely covered. Will not need to be cured further, may even have some plant life like macro algeas on it.
Go to 10 different LFS and see what they call live rock and you will see 10 very different grades of live rock. Some of it may need further curing, smell it, if it stinks then its not fully cured.
Guess I would have to say buyer beware on this issue.
Thomas