A couple of questions come to mind:
1) How did the JW's respond when the Spanish Flu was rampant 1918-19, infecting @500 million people? Did the preaching work stop?
2) If they put their money where their mouth is, why would they be afraid of death anyway? Isn't death a direct ticket to paradise? Not sure I understand why they comply with this but not with governmental orders not to preach in countries under ban...