Microsoft doesn't include the Type Cover with any Surface Pro and never has done. Aside from Microsoft's new marketing which attempts to place the 2017 Surface Pro as the 'most versatile laptop' and would therefore suggest a keyboard should be in the package, do you actually need the Type Cover?
It's a complaint that has been raised against the Surface tablet line since the launch of the original RT version. Microsoft should bundle the keyboard with the Surface Pro if it is going to persist in making laptop references.
It's a fair complaint, however there are good reasons why Microsoft might choose to do make the keyboard optional. Firstly it reinforces the message that the Surface Pro is a tablet and can do tablet things without needing anything more than the very capable onscreen keyboard and trackpad. And secondly, it allows Microsoft to compete on a like for like basis with the iPad when pricing its devices.
The Type Cover turns out to be an option which almost all Surface Pro buyers take up. Reasonably so. After all if you're going to buy a cover for your Surface you might as well get one which doubles as a pretty good keyboard, turning your tablet into a laptop at the same time.
So whilst you don't have to buy a Type Cover to go with your Surface Pro, most customers choose to do so. With Microsoft choosing to maintain peripheral compatibility across three generations of the Surface Pro now, with every sign of continuing to do so in future, at least you'll only have to do so once.