If you’re accepted, you will be early accepted into the Summer 2019 batch which begins in June. If you’re not accepted, you can apply again during the regular Summer 2019 application cycle which begins in March.

I assume that means you'll find out at the same time as everyone else - so yes, "Early Rejection"

They should add:

Early Rejection will make it even easier for students to abandon the idea of building their startup after graduation.

Then It’ll be perfectly balanced, as all thing should be.

Well then that would just be silly. A large number of YC companies don't get in the first few times they apply with an idea. Getting rejected from YC doesn't mean your startup isn't viable - it may just mean it's not ready for investment (from them) yet.