I am guessing you didn't read the books and just watched the show? or are just arguing, although I am not sure over what really as we agree the conclusion on Jon.
I am not sure how logical it is that Jon will become 'king' of the Wildlings, its not impossible although not implied either? Wildlings aren't a people that historically like to be ruled, they came together out of circumstance to escape the White Walkers.
Drogos son Rheago is dead because thats was clear in the books if not the show.