Today most licenses are of a central type so we rarely need to change their IP address as IP address of the Management server does not change that often. Still, if this happens then there is an option to change IP address or re-license the existing license. Don’t take my word for this as this is completely up to Check Point to decide but from my experience they allow to do so 6 times, after which you would need either contact them to settle this or buy a new license.