According to what you just said, even you agree there will be some uncertainties.
Please don't get me wrong, I am not trying to persuade fresh graduates from applying, but hear this:
It is a gamble.
Along the people I have met; on one side applicants whom have started preparing years ago, on the other, those whom are here because they heard someone is hiring a few months back. As stages progress the ratio of applicants from the latter diminishes.
It is not the best idea to ride a high school diploma alone into battle. You have a PPL so you are covered, but don't forget, it is hard to fly here in the first place, lets not talk about obtaining a license.
The immediate objective for a high school graduate will be to consider university education, however, applying for cadetship will mean studying and dedication. Lets say the selection takes six months to a year (from submission/ confirmation to flight grading)
If one is rejected halfway, he / she would have wasted a university semester, a delay that could have been avoided if studying for three years for an assurance and secure place in the job market is too much to ask for...
Remember, pilots don't take unnecessary risks
