If your application's delayed, it’s usually for 1 of 2 reasons: you may not have enough public watch hours (Creator Studio shows public & private combined), or our team couldn’t come to a clear decision & we need multiple reviews: https://yt.be/help/YPP-review
If you still haven’t heard back, it’s usually for 1 of 2 reasons – you don’t have enough public watch hours, or your channel requires additional, in-depth reviews since the content is close to not meeting our policies. More on these 2 topics here: https://yt.be/help/YPP-review