Sorry to hear about your loss.
I had ryes syndrome at age 10 and am now wanting to get tested for celiac. I am 99% sure I am extremely sensitive because I show all of the signs of celiac. I quit gluten and am much better now, unless I have gluten or eat somewhere where there may be cross-contamination.
I was curious about a possible link because it makes sense. There are probably compounding circumstances but it couldn't have helped that all I ate when I had the flu was cereal, toast, bagels and a few eggs.
I had lot's of asprin for the very high fever, which is what the main trigger seams to be. Lot's of kids take asprin with the flu and don't get Rye's though. Maybe the gluten is a third factor, especially if you are celiac.