Interesting idea.

If you were running your own pool then people would likely be tracking your pool and know where you're located. But if you are keeping a low profile and participating in a variety of other pools, then you might go unnoticed. But still, the pool operators might track which IPs are submitting work, and geolocate them, and see which countries are dropping in their work submissions. If you had ran all your stuff through a Chinese VPN historically, then it would make sense. Although usually you want the lowest latency possible when mining to avoid losses due to submitting stale work. A VPN would probably hurt your profits a little.