The Gaming Control Board Approval List is a monthly report, but it is not the actual approval of a strike or chip.The official approval is in a separate and individual letter sent to the mint and IGT. The letter is issued on a daily basis. Consequently, a strike might be approved on the third of the month and go in play on the fifth. We won't know of the approval until that month's approval list is published the following month.
Once a strike is approved, it is up to the casino as to when, if ever, it goes into play.