Bob, from what dealings I have had with CO GCB:
No NV gaming is not like CO!!!!!!!!!!!!!

Greg pretty much answered the question.
Yes, art work is approved several weeks before chips are made.
After chips are made a notched chip is submitted to gaming.
They have pulled several issues in the notched stage. Chips get destroyed.
They have the power to pull chips at any time after release.
To quote a poker term "Floorman's decission is final"