Wizzair will not ever guarantee the loan, that would be quite the treat, but they do guarantee a job after successful graduation or money back. Meaning a bank might just be able to finance this as you have a written guarantee to receive work and salary.
And I wholeheartedly agree with the reasoning that they must reveal the salary - from entry level on - in order to make a proper decision. If the flight training is an investment, then you need to know the returns as well.