Your License allows you to have a certain amount of active memberships so if a membership expires or is revoked then a 'replacement' token is generated so that you have the opportunity to have all of your allocated memberships active. 

For example, you have a GOLD license with 25 Memberships and 3 have expired. Your license will generate 3 'replacement' tokens so that you can have 25 active Memberships and this will show as having been issued 28 Tokens.