Let me start by saying that I don't have the strongest understanding of digital audio transmission works and how the information is encoded and decoded at both ends. However, I am in IT and I do have something of it an understanding of how TCP/IP transmission works. Built into the protocol is constant error checking to make sure the data arrives exactly how it was sent. Each packet is verified four times. I don't understand how the quality of the switch will impact the quality of encoded audio being streamed through it any more than it would affect a Microsoft word document that you are transferring from one PC to another.
There are definitely some gaps in my knowledge, so I'm not going to say "snake oil" with 100% certainty, I'm just going to say that I don't understand how a switch would affect the audio quality of a stream.