Can be a combination of factors. Someone like Gene might be able to jump in here with some specifics, but where chips exist for casinos that never opened its possible the casino either made a bad assumption they would get the licence and ordered too early, or there was not enough time to produce them between licencing and opening etc.
There have been occasions the manufacturer had to eat the chips. Sometimes they appeared later.
Or, maybe the chips were never delivered because they didnt pay 100% upfront.

Is your chip a chipco or B&G?