I am not familiar with the 1001 or the 1002 rev codes. My first thought is that it is a BCBS thing. I did a little research and I found that:
1001 means Residential Treatment, Psychiatric
1002 means Residential Treatment, SA Disorders
If BC is telling you thats what they want I would use the appropriate one for your service with BC only, and continue what you are doing with the other carriers if they are not complaining.
Hope that helps.
Michele