Laptops can be rated for whichever power level the manufacturer prefers; USB-C PD is used between the power supply and device to negotiate the maximum power level allowed for by both, so a consumer that purchases a 100W or 240W cable and power supply could still use them with a lower-rated device.
A 60W USB-C laptop can therefore stay at 60W without issue, but if a 240W laptop is produced, it should also be made to use USB-C under such a regulation.