Not exactly true.
Once there is a reasonable expectation, they are not coming back in, a casino can bring profit into revenue.
Not all casinos will take the time to do. The ones that do, do it in December.

The bankroll needed to satisfy gaming is a complicated formula and does not require 100% on hand to redeem all approved chips.

No and denom of chips issued
No of slots
No of large jackpots
No of table games and limits
Sport Book limits
Keno limits
ETC-ETC-ETC