That island is Northwest Malaysia; if they were on approach in a burning plane, they probably crashed somewhere in the northern Malacca Straits.
They just haven’t found the crash site yet. But eventually, I think they will.
Mr. Goodfellow’s hypothesis makes the most sense, and remember what happened to South African Airways Flight 295, which suffered an aboard fire believed to have ultimately caused the plane to break up after the fire burned through the hull.
Now, to be fair, they found that one pretty quick - within 12 hours.
So there’s a mystery here, but my instinct tells me it crashed at sea and it’s just a matter of finding it.
You sound the most plausible, because I think some satellite or radar would have picked up the plane, if it made it to Pakistan or one of the countries they are talking about.
The pilot seemed to be the most suspect, if it was a hijacked plane, but that does not mean the co pilot was in compliance....crashing makes more sense, even if he tried to hi jack.