According to this Q&A:
https://developer.apple.com/library/ios/qa/qa1779/_index.html
An app update is a package that is created by Apple and only contains files that have changed or are new. When a user updates their app, they only get the new files.
I've made a major update to an app, and I want a 'fresh start' with all files replaced.
Thanks for any ideas!
Chris
EDIT: I guess in the end, what I wanted to do was delete the app's own standard user defaults without having the the new version of the app do it as a matter of housekeeping. Now I know how updates actually work.
There are 3 possible situation:
Don't worry about 1-3 apple will take care of those.
For case 4 however, you need to write some code to clear/reset those files first time it loads and then set a flag somewhere (User defaults may be) to make sure you are resetting the file every single load.
If you have any assets/files that won't match any of the above let me know.