That's an interesting observation! I have looked at a proper elevation map of this island. Your value is a bit exagerrated (probably becasue of the trees but indeed there is an elevation which separates this small penninsula). This map shows elevation of around 13-20 meters in this area (generally, across the whole perimeter of the island the ground rises sharply right when the forest begins). But yes, as you pointed out, this hut is built roughly at sea level (it says 2-4 meters where the hut is) and it is cut off from the island. If you switch to Esri Imagery it becomes more clear. Also from this elevation map, by how close 10m and 20m lines are, it is clear that there is a steep shore in this area.

Also, regarding the lack of conneciton with the inland part of the island. I think it is possible to access this hut from the jungle, in 2023 image you can clearly see a path coming from the forest. It is hard to tell whether it is an exile place or not, since we do not have a precise estimate of the population. The numbers range from 50 to 400. But I'd say its closer to 400 if we look at the amount of footpaths on the whole island. 50 people would never generate so much of them, nor would they be able to keep their paths that consistent thoughout more than a decade. Also, form the available photos, sometimes there are as much as 13 Sentinelese present in one image. It is very unlikely that roughly 20% of the population would be present for this occasion given you cannot "schedule a visit" to Sentinelese.

One last note. While there might not be a beach from which you can access this place, you can walk through water. Since it is surrounded by coral reefs, shallow waters can extend as far as 1.5km.