...the new owners are changing the name of the casino.
If they are "officialy" changing the name, say "The New Hard Rock" then they would have to change all colladeral.

Even if they do change the name and chips they do not HAVE to recall the old chips. They can carry outstanding chips in the "Float" if they want to.

Example
Fiesta Rancho.
Texas bought it in 2001 from the Maloof's, carried the "Float" as is and did not recall chips until they re-racked early this year.