cool little story. also yes, you can still see the whole story after the eshop closure:

- download game and DLC
- play as normal
- buy the game
- if you get the successful purchase animation, continue
- if you get an error that game is no longer available, move on. you won't miss out on any dialogue
- go to home and try to open game
- if you had a successful purchase, you should be able to play as normal
- if you get some form of error: quit game and reinstall the DLC. it will work again when you boot it up

also works with the non-story games. keep haggling and don't just buy the games at full price just because you won't be spending money anymore.