Yes, travel insurance for Long Lama is worth having, and the honest reason is logistics rather than danger: this is a small interior settlement on the Baram river in Sarawak, reached by road or by boat rather than through any real airport, and it has no hospital of its own capable of handling a serious injury. Most travelers pass through on the way to longhouse visits or river journeys further upstream, and the practical question insurance answers is what happens if something goes wrong far from a town.
The nearest meaningful medical care sits in Miri, the coastal hub city that serves this whole stretch of northern Sarawak; anyone with an injury or illness beyond minor first aid is typically moved there by road or, where the situation is urgent enough, by air, before any decision is made about further treatment in Kuching or Kuala Lumpur. Because the route out often depends on river or road conditions rather than a scheduled flight, a policy with real medical evacuation cover, not a nominal one, matters more here than in a destination with an airport terminal minutes from a hospital.
River travel is part of the honest risk picture too. Longboats and river crossings are the normal way to reach longhouses beyond Long Lama, and conditions can change quickly after rain, so cover that does not quietly exclude local boat transport is worth confirming before you go. There are no named adventure activities to insure against here beyond ordinary river and jungle travel, so avoid a policy sold around activities you will not actually be doing.
On the practical side, note the time and place of any incident, keep receipts for any local treatment, and get written confirmation of transport used if you are moved to Miri. Check whether your existing health cover extends abroad and to Malaysia specifically, since this is not a case where you can assume a home plan simply carries over.