Actually, it is still important. While the CCS plug and adapter will slowly become irrelevant, the CCS signaling standard will remain the communication methods used by all Non-Tesla DC Charging Stations (and Tesla Superchargers when a Non-Tesla plus in). This means that you still will need to get the CCS retrofit in an older Tesla for it to be able to use Non-Tesla DC chargers. Otherwise, the plug will fit, but nothing will happen.