iPad apps are getting multiple windows, the report claims. Each one will contain sheets that are initially attached to one portion of the screen, but can be detached with a drag gesture, then becoming a card that can be moved around at will. These cards can also be stacked on top of each other, and use a depth effect to indicate which cards are on top and which are on the bottom. The browser will automatically ask to render the desktop version of a website instead of its iPhone version.
Mail improvements. In iOS 13, the Mail app is being updated with category (marketing, purchases, travel, "not important" and more) filtering and a new Read Later queue.
A standard undo gesture will make its way into iOS 13 as well. On iPad (at least), you might be able to undo and redo actions by sliding three fingers left or right on the keyboard area.
Font management will also be improved as a part of iOS 13, with a new font management panel being a part of the OS. Third-party document-based apps should get easier collaboration tools, similar to what's available in Apple's own Pages, Numbers, and Keynote apps.
Generally, the iOS 13 update seems to be geared towards various productivity functions and is focusing on new gestures. You'll drag with multiple fingers on a list or collection of items to draw a selection. This will help users differentiate between multiple Split View windows. The new feature should also remove the glare from the phone for use in low light situations, which should allow users to take advantage of Messenger regardless of where they are.
Furthermore, the report adds that font management is expected to improve on iOS 13, along with a redesigned Reminders app, improved "Hey Siri" rejection, multilingual support for keyboards and dictation, as well as more options for in-app printing controls and more. Still, it's an intriguing look as to what Apple might be unveiling on June 3rd.