The fourth-generation iPad Air has been linked to a new design that would leave it looking more like its Pro sibling. A leaker claims to have gotten hold of material that confirms this. It comprises what is touted as a hard-copy manual for the device - that, despite its lack of a home button, also makes distinct references to Touch ID for this upcoming device.
https://www.notebookcheck.net/iPad-Air-4-a-new-leak-points-to-Pro-style-bezels-and-Touch-ID.490210.0.html