Another violent incident on North Sentinel is a matter of time due to illegal fishermen
It's good to see so many people supporting no contact. Unfortunately, in my opinion, the islanders are in line for more contact with outsiders with the predictable violent results and more infection risk.
In his 2018 journal, John Allen Chau noted "numerous rocky coral that just out of the cove having lines (thick) wrapped around them" and attributed them to outside fishermen (poachers). He was probably right that non-islanders fixed those lines. They're useful moorings for larger boats that fish the area or choose to overnight there. Sentinelese are known to make their own thin ropes from natural fibers but these lines don't fit the description.
It's less than four years since three non-islanders are presumed to have died on Sentinel. Even if the fishermen carefully watch where they're going, it's a matter of time until the next fishing boat is wrecked or beached. The seas are rough, much rougher than they look from a satellite view. The area gets high winds so something as simple as engine failure is a death sentence if you're on the windward side of the shore.
A point that isn't considered enough is that the mere act of killing and burying unwanted people exposes the Sentinelese to pathogens. It's commonly thought they bring down people easily with their arrows but an arrow hit can be survivable for quite a while. The islanders need to finish off the victims at close quarters and also verify they're dead. This is where transmission of airborne disease can happen (if the victim is still breathing) and also the transfer of bacteria or blood from skin, lice from hair, etc.
Not to mention the burial act where they handle the body again.
The Sentinelese probably have some notion that foreigners mean sickness but their methods suggest they don't know how it happens.
The Andamans have a rapidly growing population and demand for protein goes up all the time. It's known some Andaman residents already resent the Sentinelese and their "exclusion zone". Local politicians are taking a more anti-Sentinelese stance. That's why I think violent clashes are bound to become a frequent, maybe yearly, event unless the Indian state cracks down hard.
Hearing that Burmese boats also come by is more bad news. Myanmar is a war zone and they're far more likely to be armed with guns than Indians.
How well do the Andamanese know North Sentinel Island? Chau's experience suggests the fishermen know it very well. The boat that took him there must have made many prior visits because they knew where to take him. Chau wasn't there to fish but to meet people - as many as possible - so his mission was opposite to the fishermen. But the fishermen, who always took care not to have run-ins with the Sentinelese, would have known where the settlements were.
The Sentinelese needless to say resent the fishing boats and probably have memorized some of them, not by the registration numbers but probably by their color, profile, etc.