Yes, a full local reset. Its an issue that plagued us for almost a year sporadically across several thousand customers. After instrumenting our app with very detailed remote logging, we were fortunate enough to catch it on one of our in-house local test iPhones. The logging showed an app with rich local state, the app close, then several minutes later the app open with no local state. Everything was wiped. This lined up with the feedback we had been receiving. Specifically for us, the push notification subscription tokens were being erased/revoked from the browser, meaning the customer couldn't receive notifications anymore. But the logging showed all local state was reset, including IndexedDb. If you dig through the Apple developer forums and StackOverflow, you will see many others complaining about this. You will also see links to resources claiming that Apple ITP does not do this for PWAs, specifically:
My personal belief is that Apple is purposefully nuking PWAs from orbit in a non-deterministic and "buggy" way because they are a threat to the app store business model, and I suspect if they frustrate enough developers, people will stay away from PWAs.
https://webkit.org/tracking-prevention/#intelligent-tracking... "Home Screen Web Application Domain Exempt From ITP". This is 100% bullshit though.
My personal belief is that Apple is purposefully nuking PWAs from orbit in a non-deterministic and "buggy" way because they are a threat to the app store business model, and I suspect if they frustrate enough developers, people will stay away from PWAs.