I'm confused, or seeing confusion, over some things in the comments here. "We don't use Safari in our app..." We're talking web apps: you know, web sites with functionality. You don't exactly have control over which browser your users use. And in iOS, everyone is using 'Safari' even if it's Firefox or Chrome wrapped around the rendering control. This means you have to assume that the policy affects any visitor from any web browser on iOS. Technically, the other browser vendors can siphon the data into other storage to their users' benefit, but I don't know how likely they are to do that, nor whether Apple would approve them with such changes.

Do you mean that you deploy a 'native' app that's really just a wrapper around a web view that would also be just Safari? Same policy applies, but now, you have the option, in native code, to siphon off data and put it into Real Storage.