"I am sure I am right,Gene can confirm. A casino has to keep cash on hand for all outstanding chips and tokens. By "recalling" them they can put the cash back in to a user account.'

The required bankroll for a NV casino is a complicated total taking in consideration, table game limits, slot jackpots, chips, keno limits, Sport book limits, etc. It will change every 4 years.
It does not require 1$ for every $1 in chip inventory.

Casino's cancel chips and tokes to reduce inventory on what is no longer in use and what is in the cage.