I see that the sample schematic for CYUSB3304 has a circuit for over-voltage protection. So, when the VBUS gets above around 5.8V, then the VBUS_US pin gets disabled. Does the chip kill the power by the PWR_EN pin to the power switch chip (U5) after VBUS_US goes low?
When the VBUS from Host on Upstream exceeds the recommended voltage range, Over Voltage Protection IC disables VBUS_US.
And YES, the VBUS on the downstream ports will be disabled by PWR_EN through power switch, if Ghost Charging is disabled.
Else if Ghost Charging is enabled, the VBUS on the downstream ports will be 5V.