That’s only half true. PWA are exempt from data storage wipe behaviour only if they have been added to the Home Screen. And as your second article points out:
> It’s important to ensure that our iOS visitor is using Safari because iOS doesn’t permit other browsers to install our awesome PWA’s!
So if the user is using Firefox or Chrome etc browser, they can’t do it. And since all browsers have to use WKWebView, the limitation applies to all browsers. Apple has basically crippled other browsers with this anti competitive behaviour.
> It’s important to ensure that our iOS visitor is using Safari because iOS doesn’t permit other browsers to install our awesome PWA’s!
So if the user is using Firefox or Chrome etc browser, they can’t do it. And since all browsers have to use WKWebView, the limitation applies to all browsers. Apple has basically crippled other browsers with this anti competitive behaviour.