Sorry, I don't really understand the question you are trying to answer - are you asking if DLP can block PS2 ports? Given that these only work for a keyboard or mouse, what are you trying to achieve re removable media?
Maybe this document is of some help to you? http://kc.mcafee.com/resources/sites/MCAFEE/content/live/PRODUCT_DOCUMENTATION/2 4000/PD24504/en_US/Implementing_McAfee_DLPe_Device_Control.pdf?searchid=13793394 38568
I'm not an expert in this product, I dare say you can probably disable the class in the device list though. It's a long time since I've used a machine with a PS2 socket on it unfortunately.
PS2 ports don't have any concept of "notification" - it's much like a serial port, it's very "dumb".
What threat are you trying to mitigate here? someone pugging in a keyboard to a headless device?
Safeboot is correct. There's no removable media mounted via the PS/2 port so the only option would be a plug and play rule to block the bus itself...
By default DLP has unmanaged device classes set to prevent an admin from unintentionally killing access to the keyboard and mouse, preventing the user from interacting with the system.