Ungrounded laptop power brick
Yes, devices with grounded plugs need ground or their mains EMI filter makes the ground to have half of mains voltage appear on e.g laptop metal parts. That is why you get shocks or may damage equipment when connecting e.g. grounded devices to your laptop while it is connected to your ground-bypassed charger.
The warning reads on almost any equipment with a grounded plug, including genuine HP chargers, and if it does not read on the device, it reads in the manuals which should be read and understood.
The point is, a device with grounded plug must not be used in ungrounded socket. I also understand this is also not always possible, and two-prong chargers that do not need ground have their own issues.