Although this information is included in the device descriptor, it doesn't produce different host action to my opinion. Particularly it's not related to VBUS requirements.
The said specification for VBUS, that the device must not drive out to this line is supplemented by the requirement to deactivate D+/D- drivers depending on the VBUS state. The conclusions for a self-powered device are: VBUS must be monitored, e. g. by a uP input pin and it must be used to control the USB interface state by hard- or software means.