I don't buy the theory.
I'm talking about the one about TOTORO being the incarnation of death, and that the girls die at the end. The TV host was very specific about all the details (including the lack of shadows at the end), but I just think they're red herrings.
There are two main reasons why I don't buy it:
1) Right after visiting their mom, the girls go back to town and meet with the grandma and the boy. They hug them.
2) Of course the girls left the corn by the window without saying hello to their parents. It's not because they can't. It's because they would have to explain how they got there. Not just the hospital, but the window in the second floor.