This makes sense, but I think it's possibly plausible that one of the other candidates might sue, if only to create a specific precedent (IIRC, in the other two cases mentioned the President was already in office, even if not for long).
I imagine a lawsuit is possible; but on what grounds? and in what court? If a losing candidate were to go into court his only argument would be something like "Though I lost the presidential election, my opponent ( and please ignore the fact that he has been duely certified as the winner of the election) has died, and I believe that I should become the next President rather then his running mate (and please ignore the fact that he has also been certified as the winner of the election and the fact that, had this untimely event occured after Inaguration day, he would become POTUS), so I ask you to set aside any claim that my opponent's running mate might have on the office of POTUS and vacate the decision of the Electoral College so that I may become president."