If you've applied before June 1st, then you should have received an email and update in Creator Studio with more information. If your application is being held for an additional review, then you'll get a second update in the near future: https://goo.gl/2icqfh
We give careful thought to every YPP application and each one needs to be manually reviewed by our team of specialists. Due to the high applicant volume, it’s taken us a while to review every channel. We’ve been sharing updates about this here: https://goo.gl/2icqfh