TS5USBC400: no power supply, what's the status of input pin?

Hi experts, 

I'm searching for a solution for my customer. please take a look at the description as below. 

this is a special case, Modem will send a signal to invoke PC, before PC wake up, there is no power to supply the board. 

I need a switch at below marked place, I think one channel is OK, but without power supply, this device's input pin need to show a high impedence, this will

block the wakeup signal go into the pin9 of U1, for some reason, pin 9 of U1 show a low impedence when no power supply. once power supply is back, this

switch can show a low impdence and RS232 signal can directly pass into the pin9.    do you have any recommendation? thanks.