It’s all about mens rea. The law distinguishes between people who provide services to anyone, and people who intentionally market their service to criminals, even under coded language. In this case the provider didn’t just allegedly market themselves to them; they also actually excluded others.
Fair, I guess, although again I’m uncomfortable with how the PKK link appears to be used as an excuse for political suppression. I think in cases like this, it would be best to order the provider to discontinue services to the specific entity in question before resorting to sanctions, since they provided services to other political groups that were not listed as “terrorists”. I’m not sure if we have any information about whether this happened or not.