CAN gateway issues only apply to new generation OEM HU's such as RNS510, RNS315, RCD510 - not aftermarket ones.
If it comes with a CAN box, this is something else. A box that converts signals so the HU integrates with the car wiring and switches off when it is meant to, integrates with cluster and dash brightness etc. Without this you would need to take a feed from a switched live so it didn't stay on, but this won't be a problem if the CAN box is provided.