Any 18 coach train will simply run empty all the time through this route. Even the one via TATA doesn't get totally occupied.
You are highlighting Bokaro but that isn't going to give this train a favour. Hardly 50 people will board the train from there(my personal experience in Ranchi int via ASN).
Also, I don't think any more trains are going to be introduced via KGP route. It's very long. Try via Arambagh, Tarakeshwar which will be completed by next year or so.