Protein skimmers might remove some particulate matter from the water I assume but, it's the 'proteins' that it really collects and removes. You are not removing those same proteins with filter media. So I'd say no, you still need a skimmer based on your bioload.
I asked because I thought I saw a BRS YouTube video where they were talking about the 10/20 biggest mistakes people make when buying/using a protein skimmer...
And I thought one of the mistakes was not taking into account your pre-skimmer filtration when deciding on which size skimmer you need...
And then Red Sea's new RollerMat says that its 200 micron fleece (when every other fleece roller manufacturer uses 50-100 micron) - makes their new RollerMat "skimmer friendly"...
Interesting. I ran filter socks for years and then just stopped. I never really noticed any negative impact on skimmer performance after I quit using them.
Similarly, the Triton method does not use filter socks if I remember this correctly.