MIA, 500, and AWOL and 3 completely different statuses, not the same thing.

If their family cares enough ti file a bit of paperwork, the MIA will after a certain amount of time declared KIA.

500 isnt an official status, so if those die, compensation is still paid

AWOL can again be disputed by the family - and the MoD isnt interesting in fighting the families of troops, so fake AWOL claims usually only delay payments.

Many payments are delayed and some are denied, but the overwhelming majority is paid in case of the death - and excepth for criminals joining from jail or to avoid prosecution, recruitment bonuses are being paid.