What do you mean by "gated" though?
What does a noise gate do to sustain? It often truncates it. Compared to the amp, the palm mutes in the KPA samples I hear sound somewhat gated. The notes between palm mutes don't have the same sustain. It comes across as a much more controlled (tighter) palm mute. However, in reality, I think most people adjust their playing based on how an amp or profile responds. In my case, I tend to compensate for this by intentionally using a less controlled palm mute to achieve the effect I want. It's also worth mentioning that this effect can be exacerbated if you're actually using a noise gate, so turning it off may alleviate it.
I don't hear the same frequency response.
I wasn't saying the frequency response in this example is identical. I was saying that even in cases where two samples share an identical frequency response, the KPA sample would still be identifiable by the above mentioned (gated palm mute) effect.