What PiXeL01 said. It couldn't apply a noise penalty to dice pools, but if the Noise was higher than the deck's DR, then it'd still lose connection and the decker would get dumpshock.
Although, I don't know where the RAW is that say Noise doesn't apply to anything in a host. Only to things part of the WAN, but that doesn't necessarily include other Persona. It also specifies "devices", and so may not apply to the host itself or files. I think it does, but like I said... This is a team question.