So you own an iPad Air or iPad Air 2 with a case and you’re thinking about upgrading to the new 9.7-inch iPad Pro. Do you need to shell out money for a new case? As usual, it depends.
The 9.7-inch iPad Pro and the iPad Air 2 have the same dimensions: 9.4 x 6.6 x 0.24 inches. So iPad Air 2 cases should fit on the 9.7-inch iPad Pro.
How functional the 9.7-inch iPad Pro is in the case, however, is another issue. The 9.7-inch iPad Pro has four speakers while the iPad Air 2 has two. An iPad Air 2 case could block the speakers at the top (vertically) of the 9.7-inch iPad Pro. Also, the 9.7-inch iPad Pro has something the iPad Air 2 doesn't: a True Tone Flash underneath the iSight camera. An iPad Air 2 case could block this flash (thanks to reader @nchia for pointing this out).
Another thing that’s probably less of a concern is the Smart Connector; a case could block it, preventing you from using an encased iPad Pro with a keyboard. Most keyboards that use the Smart Connector also serve as a case, so this probably isn’t a big issue.
With the Apple Smart Cover, Apple confirmed that the magnet alignment is different with the Smart Connector on the 9.7-inch iPad Pro, so using the iPad Air Smart Cover on a 9.7-inch iPad Pro is not recommended. With this in mind, it’s not much of a stretch to conclude that any magnetic cover that was designed for the iPad Air should not be used with the 9.7-inch iPad Pro. Apple’s 9.7-inch iPad Pro Smart Cover is $49.
Apple's iPad Air 2 Smart Case fits with the 9.7-inch iPad Pro, but the case isn't designed for the iPad's camera and flash, Smart Connector, and speakers.