Hello Sam
I wasn’t clear in my wording, I apologize. My meaning is that pass-through will not alter the DSCP values as traffic passes through the switch. I should have said, “it will allow packets to egress without modifying the DSCP value”. The Cisco documentation is excactly right, which is what I was trying to (somewhat clumsily 
) say.
I hope this has been helpful!
Laz