What do you mean by what Apple "usually" does?
- iPad releases have previously been in March, April, September, October, and November.
- MacBook releases have been in February, April, May, June, July, October, etc.
- WWDC: previously announced products include iPhone 4, MacBook Air/Pro, Mac Pro
Get it? There's no "usually."
iPhone is the only Apple product with a relatively predictable launch cadence. You looked at iPhone, which represents 2/3 of Apple's revenue and assumed iPad would have a predictable schedule, even though it represents less than 10% of Apple's revenue.
A thin-bezel iPad design isn't all that you make it out to be. I still don't understand why you think it has to come after iPhone X? Is it because you think people will buy the 10.5" iPad Pro instead of iPhone X? Or that iPhone X has thin bezels, and that will be the only major selling feature of iPhone X?
Ask yourself, is thin-bezel what will sell iPhone X? Or is the whole user experience, including iOS 11, 3D cameras, OLED, in-display Touch ID, what will sell iPhone X?