2018 Apple iPad Pro could resemble the iPhone X
As it turns out, some code discovered in the just released iOS 11.3 beta makes a reference to an unreleased "modern iPad." Now without the proper context, this means nothing. But last year, before it was unveiled, Apple referred to the iPhone X as the "modern iPhone." Reportedly, the use of the adjective "modern" is used within Apple as a designation for hardware that comes after the iPhone 8 series, such as the iPhone X (containing Face ID as opposed to Touch ID).
As for when we might see the new Apple iPad Pro introduced, there are some who expect it to happen in June at WWDC (along with the Apple iPhone SE 2), or during the unveiling of the 2018 iPhone models in September.