I was more just thinking it means he specifically died young than not being able to live without each other. She looks like she might only be in her 60s, so Aang might have died in his 40s/50s! That's hard to grasp, 'true love' or not.

I'm seriously hoping to see some elderly Toph or Suki somewhere. I'd like to see an elderly Sokka but that's probably getting my hopes up too high if his sister's already made an appearance.