Did you even read the page you linked? The only part of the entire page that refers to masks is as follows-Very good Hooray for Roscoe
I'm sure this will mean nothing as mask wearing is now a religious practice to some.
"This is irrespective of whether the person with COVID-19 or the contact was wearing a mask or whether the contact was wearing respiratory personal protective equipment (PPE)"
This is in reference to what to do if exposed. It basically says that, if exposed to someone with Covid, you should still quarantine even if they were wearing a mask. You probably think this proves your point, but it certainly doesn't.
If you click on "personal prevention strategies", masks are recommended at the top of the page. Here you go-
Now, tell me more about how the CDC says masks don't work.....