Fortunately, getting killed by the CIA by means of predator drone strike is not everybody's threat model. For others - certain French judges for example - a real threat can be getting sanctioned by the US government and completely locked out of US services.
So yes, know your threat model when picking between #Signal and #Conversations_im.
If getting killed by means of a #predatorDrone strike were among my realistic #threatModels, I'ld avoid owning a #SIM card in the first place. Which is one of the prerequisites for a Signal account. #Jabber ftw.