Quite honestly, I am not concerned about what happens to anything when someone else dies or goes into a nursing home. That’s for their family members to figure out. I assure you that my son and his family raid my pantry every time they would come to my house and were thrilled to get home canned goods.
As to the second question, I can’t imagine any kind of diet where you couldn’t have home canned home grown produce. In the event of an emergency where food was in short supply, I’m guessing many would be thankful for anything they could get and special diets may not be much consideration.
Neither of your concerns bother me at all. To me, it’s kinda like saying . . what if I stock up on Dial soap and then decide I like Caress better?
Also, when I can food or buy food, it doesn’t sit on the shelf until an emergency happens. We eat what we have and restock the shelves so it isn’t like I’m going to go to the pantry 10 years from now and decide I no longer want or can eat the things we have there.