My theory:
The Casino Queen or River Queen never existed in name.
I believe one or both names were intended to be used.

I believe the Holiday Queen collateral and chips were ordered. The Holiday people OKed the use of their name just before it opened and too late to order more collateral and chips.
It opened as Holiday Casino with collateral ordered for Holiday Queen.

I had to come to this theory because I believe Ms Williams knew what she was talking about in her talk at the convention.