This is quoted from the HPA:

The term “original numismatic item” means anything which has been a part of a coinage or issue which has been used in exchange or has been used to commemorate a person or event. Such term includes coins, tokens, paper money, and commemorative medals.

There is nothing in the definition to indicate that it has to be "government issue".

Furthermore ... casino chips are classified by the American Numismatic Association, of which the CC>CC is a member organization, as a branch of exonomia or as they are commonly known - tokens. I find nothing in the definition that excludes casino chips, although there are not explicitly mentioned.

IMHO casino chips are tokens and are covered by the HPA. But, nothing is certain until it is tested in the courts.