If the plan dove into the sea at Mach I+, they might only find a few little bitty pieces.
More than a few “little bitty pieces”.
There are probably 5,000 items on that sized aircraft that float, and would float even through and after a typhoon...
The debris might move a bit, but it will be there.
Just the bright colored floatation devises alone would number into the hundreds and be serialized...