I think so, yes. Dropsy is repeatedly described as "fatal", and much of the treatment Fritz's doctors were recommending (which he blithely ignored) in his last year was aimed at bringing the water retention down via diuretics. Everyone noticed that people who got dropsy (FW! Wilhelmine! Fritz!) tended to die, but I imagine the connection to underlying organ failure wasn't really well understood.
Re: Various questions from Mildred