Unfortunately, with some religions they override any concept of what we in the West might expect in our culture with respect to establishing cause of death, crash investigation.
This has nothing to do with religion.
What Indonesia is doing is
standard practice for large aircraft accidents in most countries (including major accidents in the U.S.) It would be highly impractical and extremely time consuming to conduct detailed autopsies -- to the point of determining the cause of death -- for all 162 victims.
Instead, an abbreviated autopsy is performed on each victim
primarily to establish the victim's identity. In Indonesia, this is done under Police jurisdiction (from DVI -- Disaster Victim Identification unit).
Typically all victims are photographed, x-rayed (including dental x-rays) and fingerprinted. DNA samples may be taken from soft tissue, especially on limbs recovered without a body. Toxicology drug/alcohol samples may be obtained from some victims (typically any identified cockpit crew).
Major internal & external injuries are also noted, along with any foreign material found (embedded debris, shrapnel), burn marks, etc. E.g., "left tibia broken, right lung lacerated, body intact, no burn marks, no water in lung".
All of the information will be consolidated into a database, for later investigation by the National Transportation Safety Committee.
As an example, a similar abbreviated process was used in the US even on the TWA800 crash -- when the FBI suspected that a bomb might have downed the airplane.